diff --git a/api/openapi.yaml b/api/openapi.yaml
index 7881e0a..1ea78b6 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -268,6 +268,51 @@ paths:
               schema: { $ref: "#/components/schemas/Dataset" }
         "400": { $ref: "#/components/responses/BadRequest" }
         "404": { $ref: "#/components/responses/NotFound" }
+    put:
+      tags: [Datasets]
+      summary: Replace a dataset's editable metadata
+      description: |
+        Updates category, name, description, and unit. Every field is
+        required; the file, file type, and processing/lifecycle state are
+        never touched here. Sending an empty string for `description` or
+        `unit` clears that (optional) field.
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema: { $ref: "#/components/schemas/DatasetPut" }
+      responses:
+        "200":
+          description: Updated
+          content:
+            application/json:
+              schema: { $ref: "#/components/schemas/Dataset" }
+        "400": { $ref: "#/components/responses/BadRequest" }
+        "404": { $ref: "#/components/responses/NotFound" }
+        "422": { $ref: "#/components/responses/ValidationError" }
+    patch:
+      tags: [Datasets]
+      summary: Partially update a dataset's editable metadata
+      description: |
+        Updates only the fields present in the body, from category, name,
+        description, and unit. The file, file type, and processing/lifecycle
+        state are never touched here. Sending an explicit `null` for
+        `description` or `unit` clears that (optional) field; omitting a
+        field leaves it unchanged.
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema: { $ref: "#/components/schemas/DatasetPatch" }
+      responses:
+        "200":
+          description: Updated
+          content:
+            application/json:
+              schema: { $ref: "#/components/schemas/Dataset" }
+        "400": { $ref: "#/components/responses/BadRequest" }
+        "404": { $ref: "#/components/responses/NotFound" }
+        "422": { $ref: "#/components/responses/ValidationError" }
     delete:
       tags: [Datasets]
       summary: Delete a dataset
@@ -572,6 +617,41 @@ components:
           type: string
           maxLength: 2000
 
+    DatasetPut:
+      type: object
+      required: [category_id, name, description, unit]
+      properties:
+        category_id:
+          type: string
+          format: uuid
+        name:
+          type: string
+          maxLength: 255
+        description:
+          type: string
+          description: An empty string clears the field.
+        unit:
+          type: string
+          description: An empty string clears the field.
+
+    DatasetPatch:
+      type: object
+      description: At least one field is required. Omitted fields are left unchanged.
+      minProperties: 1
+      properties:
+        category_id:
+          type: string
+          format: uuid
+        name:
+          type: string
+          maxLength: 255
+        description:
+          type: [string, "null"]
+          description: null clears the field.
+        unit:
+          type: [string, "null"]
+          description: null clears the field.
+
     AttributeColumn:
       type: object
       required: [name]
diff --git a/internal/repository/postgres/dataset.go b/internal/repository/postgres/dataset.go
index ae90946..08695fe 100644
--- a/internal/repository/postgres/dataset.go
+++ b/internal/repository/postgres/dataset.go
@@ -68,6 +68,23 @@ func (r *DatasetRepository) Create(ctx context.Context, d domain.Dataset) (domai
 	return out, mapError(err)
 }
 
+// UpdateFields overwrites a dataset's editable metadata columns (category,
+// name, description, unit). description and unit are nullable: a nil pointer
+// clears the column. Returns domain.ErrNotFound if the dataset does not
+// exist, or domain.ErrConflict if categoryID does not reference an existing
+// category.
+func (r *DatasetRepository) UpdateFields(ctx context.Context, id, categoryID uuid.UUID, name string, description, unit *string) (domain.Dataset, error) {
+	row := r.pool.QueryRow(ctx,
+		`UPDATE datasets
+		 SET category_id = $2, name = $3, description = $4, unit = $5, updated_at = now()
+		 WHERE id = $1
+		 RETURNING `+datasetColumns,
+		id, categoryID, name, description, unit,
+	)
+	out, err := scanDataset(row)
+	return out, mapError(err)
+}
+
 // MarkParsed stores the detected attribute columns and moves the dataset to
 // awaiting_mapping, clearing any previous parse error.
 func (r *DatasetRepository) MarkParsed(ctx context.Context, id uuid.UUID, cols []domain.AttributeColumn) error {
diff --git a/internal/service/dataset.go b/internal/service/dataset.go
index 7f0a76b..80c8d83 100644
--- a/internal/service/dataset.go
+++ b/internal/service/dataset.go
@@ -35,6 +35,7 @@ var (
 type DatasetRepository interface {
 	Create(ctx context.Context, d domain.Dataset) (domain.Dataset, error)
 	GetByID(ctx context.Context, id uuid.UUID) (domain.Dataset, error)
+	UpdateFields(ctx context.Context, id, categoryID uuid.UUID, name string, description, unit *string) (domain.Dataset, error)
 	ListSummaries(ctx context.Context, filter domain.DatasetFilter, limit, offset int) ([]domain.DatasetSummary, error)
 	Count(ctx context.Context, filter domain.DatasetFilter) (int, error)
 	Delete(ctx context.Context, id uuid.UUID) error
@@ -183,10 +184,7 @@ func (s *DatasetService) Upload(ctx context.Context, in UploadInput) (domain.Dat
 	}
 	content := io.MultiReader(bytes.NewReader(head), in.Reader)
 
-	if _, err := s.categories.GetByID(ctx, in.CategoryID); err != nil {
-		if errors.Is(err, domain.ErrNotFound) {
-			return domain.Dataset{}, fmt.Errorf("%w: category does not exist", domain.ErrValidation)
-		}
+	if err := s.ensureCategoryExists(ctx, in.CategoryID); err != nil {
 		return domain.Dataset{}, err
 	}
 
@@ -946,6 +944,81 @@ func (s *DatasetService) Get(ctx context.Context, id uuid.UUID) (domain.Dataset,
 	return s.repo.GetByID(ctx, id)
 }
 
+// DatasetUpdateInput carries the full set of editable metadata fields for a
+// PUT replace. Description and Unit being nil clears those (nullable)
+// columns.
+type DatasetUpdateInput struct {
+	CategoryID  uuid.UUID
+	Name        string
+	Description *string
+	Unit        *string
+}
+
+// Update replaces a dataset's editable metadata (category, name, description,
+// unit). File-related and lifecycle fields are untouched.
+func (s *DatasetService) Update(ctx context.Context, id uuid.UUID, in DatasetUpdateInput) (domain.Dataset, error) {
+	if err := s.ensureCategoryExists(ctx, in.CategoryID); err != nil {
+		return domain.Dataset{}, err
+	}
+	return s.repo.UpdateFields(ctx, id, in.CategoryID, in.Name, in.Description, in.Unit)
+}
+
+// DatasetPatchInput carries a sparse set of metadata field changes. A nil
+// CategoryID/Name leaves that column unchanged. Description/Unit are only
+// applied when their paired Set flag is true; a nil value with Set true
+// clears the (nullable) column.
+type DatasetPatchInput struct {
+	CategoryID     *uuid.UUID
+	Name           *string
+	Description    *string
+	DescriptionSet bool
+	Unit           *string
+	UnitSet        bool
+}
+
+// Patch applies a sparse update to a dataset's editable metadata (category,
+// name, description, unit). Fields absent from the input are left unchanged.
+func (s *DatasetService) Patch(ctx context.Context, id uuid.UUID, in DatasetPatchInput) (domain.Dataset, error) {
+	current, err := s.repo.GetByID(ctx, id)
+	if err != nil {
+		return domain.Dataset{}, err
+	}
+
+	categoryID := current.CategoryID
+	if in.CategoryID != nil {
+		categoryID = *in.CategoryID
+		if err := s.ensureCategoryExists(ctx, categoryID); err != nil {
+			return domain.Dataset{}, err
+		}
+	}
+	name := current.Name
+	if in.Name != nil {
+		name = *in.Name
+	}
+	description := current.Description
+	if in.DescriptionSet {
+		description = in.Description
+	}
+	unit := current.Unit
+	if in.UnitSet {
+		unit = in.Unit
+	}
+
+	return s.repo.UpdateFields(ctx, id, categoryID, name, description, unit)
+}
+
+// ensureCategoryExists validates that categoryID references an existing
+// category, mirroring the check performed on upload.
+func (s *DatasetService) ensureCategoryExists(ctx context.Context, categoryID uuid.UUID) error {
+	if _, err := s.categories.GetByID(ctx, categoryID); err != nil {
+		if errors.Is(err, domain.ErrNotFound) {
+			return fmt.Errorf("%w: category does not exist", domain.ErrValidation)
+		}
+		return err
+	}
+	return nil
+}
+
 // Status-wait bounds and polling cadence for long polling.
 const (
 	DefaultStatusWait  = 25 * time.Second
diff --git a/internal/service/dataset_test.go b/internal/service/dataset_test.go
index a3480f7..74aba7b 100644
--- a/internal/service/dataset_test.go
+++ b/internal/service/dataset_test.go
@@ -56,6 +56,19 @@ func (r *stubDatasetRepo) GetByID(_ context.Context, id uuid.UUID) (domain.Datas
 	return d, nil
 }
 
+func (r *stubDatasetRepo) UpdateFields(_ context.Context, id, categoryID uuid.UUID, name string, description, unit *string) (domain.Dataset, error) {
+	d, ok := r.store[id]
+	if !ok {
+		return domain.Dataset{}, domain.ErrNotFound
+	}
+	d.CategoryID = categoryID
+	d.Name = name
+	d.Description = description
+	d.Unit = unit
+	r.store[id] = d
+	return d, nil
+}
+
 func (r *stubDatasetRepo) ListSummaries(_ context.Context, filter domain.DatasetFilter, limit, offset int) ([]domain.DatasetSummary, error) {
 	r.lastFilter = filter
 	r.lastLimit = limit
@@ -1298,3 +1311,121 @@ func TestDatasetService_Delete_RemovesObject(t *testing.T) {
 		t.Fatalf("object not removed: %v", store.removed)
 	}
 }
+
+func strPtr(s string) *string { return &s }
+
+func TestDatasetService_Update_Success(t *testing.T) {
+	repo := newStubDatasetRepo()
+	id := uuid.New()
+	repo.store[id] = domain.Dataset{ID: id, Name: "Old", Description: strPtr("old desc"), Unit: strPtr("old unit")}
+	svc := newDatasetService(repo, &stubStore{}, true)
+
+	newCategory := uuid.New()
+	got, err := svc.Update(context.Background(), id, DatasetUpdateInput{
+		CategoryID:  newCategory,
+		Name:        "New",
+		Description: strPtr("new desc"),
+		Unit:        nil,
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got.CategoryID != newCategory || got.Name != "New" {
+		t.Fatalf("update not applied: %+v", got)
+	}
+	if got.Description == nil || *got.Description != "new desc" {
+		t.Fatalf("description not updated: %v", got.Description)
+	}
+	if got.Unit != nil {
+		t.Fatalf("unit should be cleared, got %v", *got.Unit)
+	}
+}
+
+func TestDatasetService_Update_MissingCategory(t *testing.T) {
+	repo := newStubDatasetRepo()
+	id := uuid.New()
+	repo.store[id] = domain.Dataset{ID: id, Name: "Old"}
+	svc := newDatasetService(repo, &stubStore{}, false)
+
+	_, err := svc.Update(context.Background(), id, DatasetUpdateInput{CategoryID: uuid.New(), Name: "New"})
+	if !errors.Is(err, domain.ErrValidation) {
+		t.Fatalf("want ErrValidation, got %v", err)
+	}
+}
+
+func TestDatasetService_Update_NotFound(t *testing.T) {
+	repo := newStubDatasetRepo()
+	svc := newDatasetService(repo, &stubStore{}, true)
+
+	_, err := svc.Update(context.Background(), uuid.New(), DatasetUpdateInput{CategoryID: uuid.New(), Name: "New"})
+	if !errors.Is(err, domain.ErrNotFound) {
+		t.Fatalf("want ErrNotFound, got %v", err)
+	}
+}
+
+func TestDatasetService_Patch_PartialUpdate(t *testing.T) {
+	repo := newStubDatasetRepo()
+	id := uuid.New()
+	origCategory := uuid.New()
+	repo.store[id] = domain.Dataset{
+		ID: id, CategoryID: origCategory, Name: "Old",
+		Description: strPtr("old desc"), Unit: strPtr("old unit"),
+	}
+	svc := newDatasetService(repo, &stubStore{}, true)
+
+	// Only Name is set; everything else must be left unchanged.
+	got, err := svc.Patch(context.Background(), id, DatasetPatchInput{Name: strPtr("New")})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got.Name != "New" {
+		t.Fatalf("name not updated: %+v", got)
+	}
+	if got.CategoryID != origCategory {
+		t.Fatalf("category should be unchanged, got %v", got.CategoryID)
+	}
+	if got.Description == nil || *got.Description != "old desc" {
+		t.Fatalf("description should be unchanged, got %v", got.Description)
+	}
+	if got.Unit == nil || *got.Unit != "old unit" {
+		t.Fatalf("unit should be unchanged, got %v", got.Unit)
+	}
+}
+
+func TestDatasetService_Patch_ClearsNullableField(t *testing.T) {
+	repo := newStubDatasetRepo()
+	id := uuid.New()
+	repo.store[id] = domain.Dataset{ID: id, Name: "Old", Description: strPtr("old desc")}
+	svc := newDatasetService(repo, &stubStore{}, true)
+
+	got, err := svc.Patch(context.Background(), id, DatasetPatchInput{DescriptionSet: true, Description: nil})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got.Description != nil {
+		t.Fatalf("description should be cleared, got %v", *got.Description)
+	}
+}
+
+func TestDatasetService_Patch_MissingCategory(t *testing.T) {
+	repo := newStubDatasetRepo()
+	id := uuid.New()
+	repo.store[id] = domain.Dataset{ID: id, Name: "Old"}
+	svc := newDatasetService(repo, &stubStore{}, false)
+
+	newCategory := uuid.New()
+	_, err := svc.Patch(context.Background(), id, DatasetPatchInput{CategoryID: &newCategory})
+	if !errors.Is(err, domain.ErrValidation) {
+		t.Fatalf("want ErrValidation, got %v", err)
+	}
+}
+
+func TestDatasetService_Patch_NotFound(t *testing.T) {
+	repo := newStubDatasetRepo()
+	svc := newDatasetService(repo, &stubStore{}, true)
+
+	_, err := svc.Patch(context.Background(), uuid.New(), DatasetPatchInput{Name: strPtr("New")})
+	if !errors.Is(err, domain.ErrNotFound) {
+		t.Fatalf("want ErrNotFound, got %v", err)
+	}
+}
diff --git a/internal/transport/http/dataset_handler.go b/internal/transport/http/dataset_handler.go
index 254919f..db3949a 100644
--- a/internal/transport/http/dataset_handler.go
+++ b/internal/transport/http/dataset_handler.go
@@ -37,6 +37,8 @@ func (h *DatasetHandler) Register(r chi.Router) {
 	r.Get("/", h.list)
 	r.Post("/", h.upload)
 	r.Get("/{id}", h.get)
+	r.Put("/{id}", h.update)
+	r.Patch("/{id}", h.patch)
 	r.Get("/{id}.geojson", h.geojson)
 	r.Get("/{id}.cog", h.cog)
 	r.Get("/{id}/status", h.status)
@@ -306,6 +308,150 @@ func (h *DatasetHandler) get(w http.ResponseWriter, r *http.Request) {
 	httputil.WriteJSON(w, http.StatusOK, dataset)
 }
 
+// datasetPutRequest is the full JSON body for PUT /datasets/{id}: every
+// editable field is required. Description and Unit are pointers so an empty
+// string is distinguishable from an absent field; a blank value clears the
+// (nullable) column. File-related and lifecycle fields are not editable here.
+type datasetPutRequest struct {
+	CategoryID  string  `json:"category_id" validate:"required,uuid"`
+	Name        string  `json:"name" validate:"required,max=255"`
+	Description *string `json:"description" validate:"required"`
+	Unit        *string `json:"unit" validate:"required"`
+}
+
+// update replaces a dataset's editable metadata (category, name, description,
+// unit).
+func (h *DatasetHandler) update(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseUUIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	req, err := httputil.DecodeJSON[datasetPutRequest](w, r)
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if err := h.validate.Struct(req); err != nil {
+		httputil.WriteValidationErrors(w, err)
+		return
+	}
+	categoryID, err := uuid.Parse(req.CategoryID)
+	if err != nil {
+		httputil.WriteError(w, http.StatusUnprocessableEntity, "category_id must be a valid UUID")
+		return
+	}
+
+	dataset, err := h.svc.Update(r.Context(), id, service.DatasetUpdateInput{
+		CategoryID:  categoryID,
+		Name:        strings.TrimSpace(req.Name),
+		Description: normalizeOptional(*req.Description),
+		Unit:        normalizeOptional(*req.Unit),
+	})
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusOK, dataset)
+}
+
+// datasetPatchFields lists the JSON keys accepted by PATCH /datasets/{id}.
+var datasetPatchFields = map[string]struct{}{
+	"category_id": {}, "name": {}, "description": {}, "unit": {},
+}
+
+// patch applies a sparse update to a dataset's editable metadata (category,
+// name, description, unit): only fields present in the body are changed.
+// Sending an explicit null for description/unit clears that column.
+func (h *DatasetHandler) patch(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseUUIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	raw, err := httputil.DecodeJSON[map[string]json.RawMessage](w, r)
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if len(raw) == 0 {
+		httputil.WriteError(w, http.StatusBadRequest, "request body must include at least one field")
+		return
+	}
+
+	var in service.DatasetPatchInput
+	for key, val := range raw {
+		if _, ok := datasetPatchFields[key]; !ok {
+			httputil.WriteError(w, http.StatusUnprocessableEntity, "unknown field: "+key)
+			return
+		}
+		switch key {
+		case "category_id":
+			var s string
+			if err := json.Unmarshal(val, &s); err != nil || s == "" {
+				httputil.WriteError(w, http.StatusUnprocessableEntity, "category_id must be a valid UUID")
+				return
+			}
+			cid, err := uuid.Parse(s)
+			if err != nil {
+				httputil.WriteError(w, http.StatusUnprocessableEntity, "category_id must be a valid UUID")
+				return
+			}
+			in.CategoryID = &cid
+		case "name":
+			var s string
+			if err := json.Unmarshal(val, &s); err != nil || strings.TrimSpace(s) == "" {
+				httputil.WriteError(w, http.StatusUnprocessableEntity, "name must not be blank")
+				return
+			}
+			name := strings.TrimSpace(s)
+			in.Name = &name
+		case "description":
+			desc, err := decodeOptionalPatchString(val)
+			if err != nil {
+				httputil.WriteError(w, http.StatusUnprocessableEntity, "description must be a string or null")
+				return
+			}
+			in.Description, in.DescriptionSet = desc, true
+		case "unit":
+			unit, err := decodeOptionalPatchString(val)
+			if err != nil {
+				httputil.WriteError(w, http.StatusUnprocessableEntity, "unit must be a string or null")
+				return
+			}
+			in.Unit, in.UnitSet = unit, true
+		}
+	}
+
+	dataset, err := h.svc.Patch(r.Context(), id, in)
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusOK, dataset)
+}
+
+// normalizeOptional trims s and returns nil when blank, so an empty string
+// clears a nullable column rather than being stored verbatim.
+func normalizeOptional(s string) *string {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return nil
+	}
+	return &s
+}
+
+// decodeOptionalPatchString unmarshals a PATCH field that may be a JSON string
+// or null, returning nil (clear the column) for null or a blank string.
+func decodeOptionalPatchString(raw json.RawMessage) (*string, error) {
+	if string(raw) == "null" {
+		return nil, nil
+	}
+	var s string
+	if err := json.Unmarshal(raw, &s); err != nil {
+		return nil, err
+	}
+	return normalizeOptional(s), nil
+}
+
 // geojson returns the dataset's pre-assembled GeoJSON FeatureCollection (RFC
 // 7946), generated and stored at processing time. A vector_with_kato dataset's
 // collection joins the districts table on KATO code (one feature per KATO with