diff --git a/app/schema/mutations/__init__.py b/app/schema/mutations/__init__.py
index ca0a9ae..7cda91d 100644
--- a/app/schema/mutations/__init__.py
+++ b/app/schema/mutations/__init__.py
@@ -1,3 +1,4 @@
+from .close_todo import CloseTodo
 from .create_todo import CreateTodo
 from .delete_todo import DeleteTodo
-from .update_todo import UpdateTodo
\ No newline at end of file
+from .update_todo import UpdateTodo
diff --git a/app/schema/mutations/close_todo.py b/app/schema/mutations/close_todo.py
new file mode 100644
index 0000000..0489dd9
--- /dev/null
+++ b/app/schema/mutations/close_todo.py
@@ -0,0 +1,15 @@
+import graphene
+
+from app.schema.types.todo import TodoType
+from app.usecases.close_todo import close_todo
+
+
+class CloseTodo(graphene.Mutation):
+    class Arguments:
+        todo_id = graphene.String(required=True)
+
+    todo = graphene.Field(TodoType)
+
+    def mutate(self, info, todo_id: str):
+        todo = close_todo(todo_id)
+        return CloseTodo(todo=todo)
diff --git a/app/schema/mutations/mutations.py b/app/schema/mutations/mutations.py
index c98e46b..3a92415 100644
--- a/app/schema/mutations/mutations.py
+++ b/app/schema/mutations/mutations.py
@@ -1,9 +1,10 @@
 import graphene
 
-from . import CreateTodo, DeleteTodo, UpdateTodo
+from . import CreateTodo, DeleteTodo, UpdateTodo, CloseTodo
 
 
 class Mutations(graphene.ObjectType):
     create_todo = CreateTodo.Field()
     update_todo = UpdateTodo.Field()
     delete_todo = DeleteTodo.Field()
+    close_todo = CloseTodo.Field()
diff --git a/app/usecases/close_todo.py b/app/usecases/close_todo.py
new file mode 100644
index 0000000..7c99727
--- /dev/null
+++ b/app/usecases/close_todo.py
@@ -0,0 +1,11 @@
+from app.models.todo import Todo
+from app.repositories.todos import get_todo_by_id, todo_exists
+
+
+def close_todo(todo_id: str) -> Todo:
+    if not todo_exists(todo_id):
+        return None
+
+    todo = get_todo_by_id(todo_id)
+    todo.is_done = True
+    return todo