diff --git a/js/components/operatorSignIn/list.tsx b/js/components/operatorSignIn/list.tsx
index c6c930db..6ec0b86a 100644
--- a/js/components/operatorSignIn/list.tsx
+++ b/js/components/operatorSignIn/list.tsx
@@ -45,7 +45,7 @@ export const List = ({ line }: { line: HeavyRailLine }): ReactElement => {
                 .replace(/ /g, "")}
             </td>
             <td className="fs-mask border-y md:border-x p-1 break-words [hyphenate-character:'']">
-              {si.signed_in_by_user.replace(
+              {si.signed_in_by.replace(
                 /@/g,
                 // 173 is a soft hyphen, which here acts as a breaking suggestion
                 // We are hiding the hyphen above with CSS
diff --git a/js/models/signin.ts b/js/models/signin.ts
index 5feb6275..8d9dd022 100644
--- a/js/models/signin.ts
+++ b/js/models/signin.ts
@@ -3,7 +3,7 @@ import { z } from "zod";
 export const SignIn = z.object({
   rail_line: z.enum(["blue", "orange", "red"]),
   signed_in_at: z.string(),
-  signed_in_by_user: z.string(),
+  signed_in_by: z.string(),
   signed_in_employee: z.string(),
 });
 
diff --git a/js/test/components/operatorSignIn/list.test.tsx b/js/test/components/operatorSignIn/list.test.tsx
index aa1043d1..03aed850 100644
--- a/js/test/components/operatorSignIn/list.test.tsx
+++ b/js/test/components/operatorSignIn/list.test.tsx
@@ -24,7 +24,7 @@ jest.mock("../../../hooks/useSignIns", () => ({
         signed_in_at: DateTime.fromISO("2024-07-22T12:45:52.000-04:00", {
           zone: "America/New_York",
         }),
-        signed_in_by_user: "user@example.com",
+        signed_in_by: "user@example.com",
         signed_in_employee: EMPLOYEES[0].badge,
       },
     ],
diff --git a/js/test/hooks/useSignins.test.ts b/js/test/hooks/useSignins.test.ts
index a86ee572..402a3c1d 100644
--- a/js/test/hooks/useSignins.test.ts
+++ b/js/test/hooks/useSignins.test.ts
@@ -13,7 +13,7 @@ const TEST_DATA = {
     {
       rail_line: "blue",
       signed_in_at: "2024-07-22T16:42:32Z",
-      signed_in_by_user: "user@example.com",
+      signed_in_by: "user@example.com",
       signed_in_employee: "123",
     },
   ],
diff --git a/lib/orbit_web/controllers/sign_in_controller.ex b/lib/orbit_web/controllers/sign_in_controller.ex
index a6116854..1fe7fbe4 100644
--- a/lib/orbit_web/controllers/sign_in_controller.ex
+++ b/lib/orbit_web/controllers/sign_in_controller.ex
@@ -31,16 +31,29 @@ defmodule OrbitWeb.SignInController do
                 ^start_datetime <= si.signed_in_at and
                   si.signed_in_at < ^end_datetime and
                   si.rail_line == ^rail_line,
-              preload: [:signed_in_employee, :signed_in_by_user],
-              order_by: [desc: :signed_in_at]
+              join: e in assoc(si, :signed_in_employee),
+              join: u in assoc(si, :signed_in_by_user),
+              preload: [signed_in_employee: e, signed_in_by_user: u],
+              left_join: signed_in_by_employee in Employee,
+              on: u.email == signed_in_by_employee.email,
+              order_by: [desc: :signed_in_at],
+              select: %{
+                signin: si,
+                signed_in_by_employee: signed_in_by_employee
+              }
             )
           )
-          |> Enum.map(fn si ->
+          |> Enum.map(fn i ->
             %{
-              rail_line: si.rail_line,
-              signed_in_at: DateTime.to_iso8601(si.signed_in_at),
-              signed_in_by_user: si.signed_in_by_user.email,
-              signed_in_employee: si.signed_in_employee.badge_number
+              rail_line: i.signin.rail_line,
+              signed_in_at: DateTime.to_iso8601(i.signin.signed_in_at),
+              signed_in_by:
+                if i.signed_in_by_employee do
+                  Employee.display_name(i.signed_in_by_employee)
+                else
+                  i.signin.signed_in_by_user.email
+                end,
+              signed_in_employee: i.signin.signed_in_employee.badge_number
             }
           end)
       }
diff --git a/test/orbit_web/controllers/sign_in_controller_test.exs b/test/orbit_web/controllers/sign_in_controller_test.exs
index 2416b857..7fe17258 100644
--- a/test/orbit_web/controllers/sign_in_controller_test.exs
+++ b/test/orbit_web/controllers/sign_in_controller_test.exs
@@ -27,7 +27,7 @@ defmodule OrbitWeb.SignInControllerTest do
                  %{
                    "rail_line" => "blue",
                    "signed_in_at" => _date,
-                   "signed_in_by_user" => _user,
+                   "signed_in_by" => _user,
                    "signed_in_employee" => _badge
                  }
                ]
@@ -64,6 +64,47 @@ defmodule OrbitWeb.SignInControllerTest do
              } = json_response(conn, 200)
     end
 
+    @tag :authenticated
+    test "shows officials' names if available", %{conn: conn} do
+      insert(:employee, email: "test@example.com")
+
+      insert(:operator_sign_in,
+        signed_in_at: DateTime.new!(~D[2024-07-21], ~T[12:00:00], @timezone),
+        signed_in_by_user: build(:user, email: "test@example.com")
+      )
+
+      conn = get(conn, ~p"/api/signin", %{"line" => "blue", "service_date" => "2024-07-21"})
+
+      assert %{
+               "data" => [
+                 %{
+                   "signed_in_by" => "Preferredy Person"
+                 }
+               ]
+             } = json_response(conn, 200)
+    end
+
+    @tag :authenticated
+    test "shows official's email address if name is unavailable", %{conn: conn} do
+      insert(:operator_sign_in,
+        signed_in_at: DateTime.new!(~D[2024-07-21], ~T[12:00:00], @timezone),
+        signed_in_by_user:
+          build(:user, %{
+            email: "does_not_exist_im_fairly_certain@example.com"
+          })
+      )
+
+      conn = get(conn, ~p"/api/signin", %{"line" => "blue", "service_date" => "2024-07-21"})
+
+      assert %{
+               "data" => [
+                 %{
+                   "signed_in_by" => "does_not_exist_im_fairly_certain@example.com"
+                 }
+               ]
+             } = json_response(conn, 200)
+    end
+
     @tag :authenticated
     test "sorted by signed_in_at descending (recent first)", %{conn: conn} do
       insert(:operator_sign_in,