diff --git a/lib/ash.ex b/lib/ash.ex
index 040e0e613..b2642cee0 100644
--- a/lib/ash.ex
+++ b/lib/ash.ex
@@ -4242,6 +4242,12 @@ defmodule Ash do
   end
 
   @transaction_opts_schema [
+    tenant: [
+      type: {:protocol, Ash.ToTenant},
+      doc: """
+      The tenant, placed on the transaction reason for data layers that select a connection per tenant.
+      """
+    ],
     timeout: [
       type: :timeout,
       doc: """
@@ -4328,7 +4334,7 @@ defmodule Ash do
                resource_or_resources,
                func,
                opts[:timeout],
-               %{type: :custom, metadata: %{}}
+               %{type: :custom, metadata: %{}, tenant: opts[:tenant]}
              ) do
         if opts[:return_notifications?] do
           notifications = Process.delete(:ash_notifications) || []
@@ -4431,7 +4437,7 @@ defmodule Ash do
                resource_or_resources,
                func,
                opts[:timeout],
-               %{type: :custom, metadata: %{}},
+               %{type: :custom, metadata: %{}, tenant: opts[:tenant]},
                rollback_on_error?: true
              ) do
         if opts[:return_notifications?] do
diff --git a/lib/ash/actions/action.ex b/lib/ash/actions/action.ex
index 3cf66c8d2..da39da93a 100644
--- a/lib/ash/actions/action.ex
+++ b/lib/ash/actions/action.ex
@@ -216,6 +216,7 @@ defmodule Ash.Actions.Action do
                 input: input,
                 actor: opts[:actor]
               },
+              tenant: input.tenant,
               data_layer_context: input.context[:data_layer] || %{}
             },
             rollback_on_error?: false
diff --git a/lib/ash/actions/create/bulk.ex b/lib/ash/actions/create/bulk.ex
index 4ab563fe0..3fb6fb6ca 100644
--- a/lib/ash/actions/create/bulk.ex
+++ b/lib/ash/actions/create/bulk.ex
@@ -80,6 +80,7 @@ defmodule Ash.Actions.Create.Bulk do
                 action: action.name,
                 actor: opts[:actor]
               },
+              tenant: opts[:tenant],
               data_layer_context: opts[:data_layer_context] || %{}
             },
             rollback_on_error?: false
@@ -671,6 +672,7 @@ defmodule Ash.Actions.Create.Bulk do
               action: action.name,
               actor: opts[:actor]
             },
+            tenant: opts[:tenant],
             data_layer_context: opts[:data_layer_context] || context
           },
           rollback_on_error?: false
diff --git a/lib/ash/actions/destroy/bulk.ex b/lib/ash/actions/destroy/bulk.ex
index 2cd52cff6..e8b1027bf 100644
--- a/lib/ash/actions/destroy/bulk.ex
+++ b/lib/ash/actions/destroy/bulk.ex
@@ -356,6 +356,7 @@ defmodule Ash.Actions.Destroy.Bulk do
                         action: atomic_changeset.action.name,
                         actor: opts[:actor]
                       },
+                      tenant: opts[:tenant],
                       data_layer_context: opts[:data_layer_context] || %{}
                     },
                     rollback_on_error?: false
@@ -539,6 +540,7 @@ defmodule Ash.Actions.Destroy.Bulk do
                   action: action.name,
                   actor: opts[:actor]
                 },
+                tenant: opts[:tenant],
                 data_layer_context: opts[:data_layer_context] || %{}
               },
               rollback_on_error?: false
@@ -1644,6 +1646,7 @@ defmodule Ash.Actions.Destroy.Bulk do
               action: action.name,
               actor: opts[:actor]
             },
+            tenant: opts[:tenant],
             data_layer_context: opts[:data_layer_context] || context
           },
           rollback_on_error?: false
diff --git a/lib/ash/actions/read/read.ex b/lib/ash/actions/read/read.ex
index 9cfdd29c9..318260653 100644
--- a/lib/ash/actions/read/read.ex
+++ b/lib/ash/actions/read/read.ex
@@ -1599,6 +1599,7 @@ defmodule Ash.Actions.Read do
                 resource: query.resource,
                 action: query.action.name
               },
+              tenant: query.tenant,
               data_layer_context: query.context[:data_layer]
             },
             rollback_on_error?: false
diff --git a/lib/ash/actions/update/bulk.ex b/lib/ash/actions/update/bulk.ex
index 763b12e1a..e0503bb44 100644
--- a/lib/ash/actions/update/bulk.ex
+++ b/lib/ash/actions/update/bulk.ex
@@ -368,6 +368,7 @@ defmodule Ash.Actions.Update.Bulk do
                         action: atomic_changeset.action.name,
                         actor: opts[:actor]
                       },
+                      tenant: opts[:tenant],
                       data_layer_context: opts[:data_layer_context] || %{}
                     },
                     rollback_on_error?: false
@@ -594,6 +595,7 @@ defmodule Ash.Actions.Update.Bulk do
                   action: action.name,
                   actor: opts[:actor]
                 },
+                tenant: opts[:tenant],
                 data_layer_context: opts[:data_layer_context] || %{}
               },
               rollback_on_error?: false
@@ -2021,6 +2023,7 @@ defmodule Ash.Actions.Update.Bulk do
               action: action.name,
               actor: opts[:actor]
             },
+            tenant: opts[:tenant],
             data_layer_context: opts[:data_layer_context] || context
           },
           rollback_on_error?: false
diff --git a/lib/ash/actions/update/update_many.ex b/lib/ash/actions/update/update_many.ex
index cf234f90b..26d29f060 100644
--- a/lib/ash/actions/update/update_many.ex
+++ b/lib/ash/actions/update/update_many.ex
@@ -122,7 +122,12 @@ defmodule Ash.Actions.Update.UpdateMany do
          atomic_notifications ++ manual_notifications}
       end,
       nil,
-      %{type: :bulk_update, metadata: %{resource: resource, action: action.name}}
+      %{
+        type: :bulk_update,
+        metadata: %{resource: resource, action: action.name},
+        tenant: opts[:tenant],
+        data_layer_context: opts[:data_layer_context] || %{}
+      }
     )
     |> case do
       {:ok, {records, errors, notifications}} -> {records, errors, notifications}
diff --git a/lib/ash/changeset/changeset.ex b/lib/ash/changeset/changeset.ex
index f0016a9ba..27d37d9f2 100644
--- a/lib/ash/changeset/changeset.ex
+++ b/lib/ash/changeset/changeset.ex
@@ -4685,11 +4685,9 @@ defmodule Ash.Changeset do
               end
             end,
             changeset.timeout || :infinity,
-            Map.put(
-              opts[:transaction_metadata],
-              :data_layer_context,
-              changeset.context[:data_layer] || %{}
-            ),
+            opts[:transaction_metadata]
+            |> Map.put(:data_layer_context, changeset.context[:data_layer] || %{})
+            |> Map.put(:tenant, changeset.tenant),
             rollback_on_error?: false
           )
           |> case do
diff --git a/lib/ash/data_layer/data_layer.ex b/lib/ash/data_layer/data_layer.ex
index fb9b280f6..47631a301 100644
--- a/lib/ash/data_layer/data_layer.ex
+++ b/lib/ash/data_layer/data_layer.ex
@@ -16,6 +16,7 @@ defmodule Ash.DataLayer do
           %{
             required(:type) => :create,
             required(:metadata) => %{resource: Ash.Resource.t(), action: atom},
+            optional(:tenant) => term(),
             optional(:data_layer_context) => %{}
           }
           | %{
@@ -26,6 +27,7 @@ defmodule Ash.DataLayer do
                 record: Ash.Resource.Record.t(),
                 actor: term()
               },
+              optional(:tenant) => term(),
               optional(:data_layer_context) => %{}
             }
           | %{
@@ -36,6 +38,7 @@ defmodule Ash.DataLayer do
                 record: Ash.Resource.Record.t(),
                 actor: term()
               },
+              optional(:tenant) => term(),
               optional(:data_layer_context) => %{}
             }
           | %{
@@ -45,6 +48,7 @@ defmodule Ash.DataLayer do
                 query: Ash.Query.t(),
                 actor: term()
               },
+              optional(:tenant) => term(),
               optional(:data_layer_context) => %{}
             }
           | %{
@@ -55,6 +59,7 @@ defmodule Ash.DataLayer do
                 action: atom,
                 actor: term()
               },
+              optional(:tenant) => term(),
               optional(:data_layer_context) => %{}
             }
           | %{
@@ -64,10 +69,19 @@ defmodule Ash.DataLayer do
                 flow: module(),
                 actor: term()
               },
+              optional(:tenant) => term(),
               optional(:data_layer_context) => %{}
             }
-          | %{required(:type) => :custom, required(:metadata) => map()}
-          | %{required(:type) => atom, required(:metadata) => map()}
+          | %{
+              required(:type) => :custom,
+              required(:metadata) => map(),
+              optional(:tenant) => term()
+            }
+          | %{
+              required(:type) => atom,
+              required(:metadata) => map(),
+              optional(:tenant) => term()
+            }
 
   @type combination_type :: :union | :union_all | :intersection