diff --git a/master_changes.md b/master_changes.md
index 082f8428b25..81a7058ffa4 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -102,6 +102,7 @@ users)
   * [BUG] When reinstalling a package that has a dirty source, if uncommitted changes are the same than the ones stored in opam's cache, opam consider that it is up to date and nothing is updated [4879 @rjbou]
   * [BUG] Handle external dependencies when updating switch state pin status (all pins), instead as a post pin action (only when called with `opam pin` [#5047 @rjbou - fix #5046]
   * Allow opam pin remove to take a package (<pkg>.<version>) as argument [#5325 @kit-ty-kate]
+  * ◈ Add opam pin remove --all to remove all the pinned packages from a switch [#5308 @kit-ty-kate]
 
 ## List
   * Some optimisations to 'opam list --installable' queries combined with other filters [#4882 @altgr - fix #4311]
@@ -577,3 +578,4 @@ users)
   * `OpamCompat`: add `Int.equal` (for ocaml < 4.12)
   * `OpamFilename.clean_dir`: as the directory is recreated after removal, checks that the directory exists beforhand. It avoid creating a new empty directory uselessly [#4967 @rjbou]
   * `OpamStd.Map`: add `filter_map` [#5337 @rjbou]
+  * `OpamStd.Set`: Add `to_list_map` [#5308 @kit-ty-kate]
diff --git a/src/client/opamCommands.ml b/src/client/opamCommands.ml
index ac3cd5eb386..51ba9737ca0 100644
--- a/src/client/opamCommands.ml
+++ b/src/client/opamCommands.ml
@@ -3184,6 +3184,10 @@ let pin ?(unpin_only=false) cli =
        changes, and may also be used to keep a package that was removed \
        upstream."
   in
+  let all =
+    mk_flag ~cli (cli_from cli2_2) ["all"]
+      "When unpinning, removes all pins in the given switch."
+  in
   let guess_names kind ?locked ~recurse ?subpath url k =
     let found, cleanup =
       match OpamUrl.local_dir url with
@@ -3300,7 +3304,7 @@ let pin ?(unpin_only=false) cli =
   let pin
       global_options build_options
       kind edit no_act dev_repo print_short recurse subpath normalise
-      with_version current
+      with_version current all
       command params () =
     apply_global_options cli global_options;
     apply_build_options cli build_options;
@@ -3317,6 +3321,10 @@ let pin ?(unpin_only=false) cli =
         `list
       | Some `scan, [url] ->
         `scan url
+      | Some `remove, [] when all ->
+        `remove_all
+      | _, _ when all ->
+        `incorrect
       | Some `remove, (_::_ as arg) ->
         `remove arg
       | Some `edit, [nv]  ->
@@ -3418,6 +3426,14 @@ let pin ?(unpin_only=false) cli =
       else
         (OpamSwitchState.drop @@ OpamClient.PIN.unpin st ~action to_unpin;
          `Ok ())
+    | `remove_all ->
+      OpamGlobalState.with_ `Lock_none @@ fun gt ->
+      OpamSwitchState.with_ `Lock_write gt @@ fun st ->
+      let to_unpin =
+        OpamPackage.Set.to_list_map OpamPackage.name (OpamPinned.packages st)
+      in
+      OpamSwitchState.drop @@ OpamClient.PIN.unpin st ~action to_unpin;
+      `Ok ()
     | `edit nv  ->
       (match (fst package) nv with
        | `Ok (name, version) ->
@@ -3515,7 +3531,7 @@ let pin ?(unpin_only=false) cli =
           $global_options cli $build_options cli
           $kind $edit $no_act $dev_repo $print_short_flag cli cli_original
           $recurse cli $subpath cli
-          $normalise $with_version $current
+          $normalise $with_version $current $all
           $command $params)
 
 (* SOURCE *)
diff --git a/src/core/opamStd.ml b/src/core/opamStd.ml
index 3d5a65ac425..6d42782a55b 100644
--- a/src/core/opamStd.ml
+++ b/src/core/opamStd.ml
@@ -16,6 +16,7 @@ module type SET = sig
   val choose_one : t -> elt
   val choose_opt : t -> elt option
   val of_list: elt list -> t
+  val to_list_map: (elt -> 'b) -> t -> 'b list
   val to_string: t -> string
   val to_json: t OpamJson.encoder
   val of_json: t OpamJson.decoder
@@ -222,6 +223,9 @@ module Set = struct
     let of_list l =
       List.fold_left (fun set e -> add e set) empty l
 
+    let to_list_map f set =
+      fold (fun x acc -> f x :: acc) set []
+
     let to_string s =
       if S.cardinal s > max_print then
         Printf.sprintf "%d elements" (S.cardinal s)
diff --git a/src/core/opamStd.mli b/src/core/opamStd.mli
index 34a40ec58a1..06ddac456c7 100644
--- a/src/core/opamStd.mli
+++ b/src/core/opamStd.mli
@@ -29,6 +29,7 @@ module type SET = sig
   val choose_opt: t -> elt option
 
   val of_list: elt list -> t
+  val to_list_map: (elt -> 'b) -> t -> 'b list
   val to_string: t -> string
   val to_json: t OpamJson.encoder
   val of_json: t OpamJson.decoder
diff --git a/tests/reftests/pin.test b/tests/reftests/pin.test
index 1490a2f2fd1..88e68d455e5 100644
--- a/tests/reftests/pin.test
+++ b/tests/reftests/pin.test
@@ -176,13 +176,61 @@ echo "another-inexistant" "inexistant"
 -> installed bar.dev
 Done.
 ### : Test opam pin remove <pkg>.<version>
+### opam pin remove --no-action bar.dev
+Ok, bar is no longer pinned to file://${BASEDIR}/bar (version dev)
+### opam pin remove --no-action nip.wrong-version
+[ERROR] nip is pinned but not to version wrong-version. Skipping.
+# Return code 2 #
+### : Test opam pin remove --all
+### OPAMNODEPEXTS=1
+### opam pin add --no-action bar.dev ./bar
+[bar.dev] synchronised (file://${BASEDIR}/bar)
+bar is now pinned to file://${BASEDIR}/bar (version dev)
 ### opam pin
 bar.dev    rsync             file://${BASEDIR}/bar
 foo.1      local definition
 nip.dev    rsync             file://${BASEDIR}/nip
 qux.dev    rsync             file://${BASEDIR}/qux
-### opam pin remove --no-action bar.dev
+### opam pin remove --no-action --all
+Ok, qux is no longer pinned to file://${BASEDIR}/qux (version dev)
+Ok, nip is no longer pinned to file://${BASEDIR}/nip (version dev)
+Ok, foo is no longer pinned locally (version 1)
 Ok, bar is no longer pinned to file://${BASEDIR}/bar (version dev)
-### opam pin remove --no-action nip.wrong-version
-[ERROR] nip is pinned but not to version wrong-version. Skipping.
+### opam pin
+### opam pin ./bar
+The following additional pinnings are required by bar.dev:
+  - qux.dev at file://${BASEDIR}/qux
+Pin and install them? [y/n] y
+[qux.dev] synchronised (no changes)
+qux is now pinned to file://${BASEDIR}/qux (version dev)
+bar is now pinned to file://${BASEDIR}/bar (version dev)
+
+Already up-to-date.
+Nothing to do.
+### opam pin --current foo
+foo is now pinned locally (version 1)
+### opam pin
+bar.dev    rsync             file://${BASEDIR}/bar
+foo.1      local definition
+qux.dev    rsync             file://${BASEDIR}/qux
+### opam pin remove --all foo
+opam: opamMain.exe: Too many arguments.
+      Usage: opamMain.exe pin [OPTION]... remove PACKAGES...|TARGET
+      
 # Return code 2 #
+### opam pin remove --all
+Ok, qux is no longer pinned to file://${BASEDIR}/qux (version dev)
+Ok, foo is no longer pinned locally (version 1)
+Ok, bar is no longer pinned to file://${BASEDIR}/bar (version dev)
+The following actions will be performed:
+=== remove 3 packages
+  - remove bar dev
+  - remove foo 1
+  - remove qux dev
+
+<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+-> removed   bar.dev
+-> removed   foo.1
+-> removed   qux.dev
+Done.
+### opam pin