diff --git a/c_glib/plasma-glib/client.cpp b/c_glib/plasma-glib/client.cpp
index 26476f4d6b51d..1cc3b6a80a65a 100644
--- a/c_glib/plasma-glib/client.cpp
+++ b/c_glib/plasma-glib/client.cpp
@@ -35,6 +35,9 @@ G_BEGIN_DECLS
  * @title: Client related classes
  * @include: plasma-glib/plasma-glib.h
  *
+ * Apache Arrow Plasma C GLib is deprecated since 10.0.0. This will be
+ * removed from 12.0.0 or so.
+ *
  * #GPlasmaClientOptions is a class for customizing plasma store
  * connection.
  *
diff --git a/c_glib/plasma-glib/meson.build b/c_glib/plasma-glib/meson.build
index cf811d42b7220..df2b67b9c2610 100644
--- a/c_glib/plasma-glib/meson.build
+++ b/c_glib/plasma-glib/meson.build
@@ -17,6 +17,9 @@
 # specific language governing permissions and limitations
 # under the License.
 
+warning('Apache Arrow Plasma C GLib is deprecated since 10.0.0. ' +
+        'This will be removed from 12.0.0 or so.')
+
 project_name = 'plasma-glib'
 
 sources = files(
diff --git a/c_glib/plasma-glib/object.cpp b/c_glib/plasma-glib/object.cpp
index 121afb1cf84a0..8bf0d4b0772ce 100644
--- a/c_glib/plasma-glib/object.cpp
+++ b/c_glib/plasma-glib/object.cpp
@@ -30,6 +30,9 @@ G_BEGIN_DECLS
  * @title: Object related classes
  * @include: plasma-glib/plasma-glib.h
  *
+ * Apache Arrow Plasma C GLib is deprecated since 10.0.0. This will be
+ * removed from 12.0.0 or so.
+ *
  * #GPlasmaObjectID is a class for an object ID.
  *
  * #GPlasmaObject is a base class for an object stored in plasma store.