diff --git a/src/registrar/forms/domain.py b/src/registrar/forms/domain.py
index a7a006788..84fcbe973 100644
--- a/src/registrar/forms/domain.py
+++ b/src/registrar/forms/domain.py
@@ -417,7 +417,7 @@ class SeniorOfficialContactForm(ContactForm):
             # This action should be blocked by the UI, as the text fields are readonly.
             # If they get past this point, we forbid it this way.
             # This could be malicious, so lets reserve information for the backend only.
-            raise ValueError("Senior Official cannot be modified for federal or tribal domains.")
+            raise ValueError("Senior official cannot be modified for federal or tribal domains.")
         elif db_so.has_more_than_one_join("information_senior_official"):
             # Handle the case where the domain information object is available and the SO Contact
             # has more than one joined object.
diff --git a/src/registrar/templates/includes/senior_official.html b/src/registrar/templates/includes/senior_official.html
index fda97b6a9..98afa4dec 100644
--- a/src/registrar/templates/includes/senior_official.html
+++ b/src/registrar/templates/includes/senior_official.html
@@ -4,7 +4,7 @@
     {% include "includes/form_errors.html" with form=form %}
 {% endif %}
 
-<h1>Senior Official</h1>
+<h1>Senior official</h1>
 
 <p>
     Your senior official is a person within your organization who can authorize domain requests.
diff --git a/src/registrar/templates/portfolio_senior_official.html b/src/registrar/templates/portfolio_senior_official.html
index 6793587bd..51ef83be5 100644
--- a/src/registrar/templates/portfolio_senior_official.html
+++ b/src/registrar/templates/portfolio_senior_official.html
@@ -1,7 +1,7 @@
 {% extends 'portfolio_base.html' %}
 {% load static field_helpers%}
 
-{% block title %}Senior Official | {{ portfolio.name }}{% endblock %}
+{% block title %}Senior official | {{ portfolio.name }}{% endblock %}
 
 {% load static %}
 
diff --git a/src/registrar/tests/test_api.py b/src/registrar/tests/test_api.py
index 0025bc902..f6a14aad9 100644
--- a/src/registrar/tests/test_api.py
+++ b/src/registrar/tests/test_api.py
@@ -64,4 +64,4 @@ class GetSeniorOfficialJsonTest(TestCase):
         response = self.client.get(self.api_url, {"agency_name": "Non-Federal Agency"})
         self.assertEqual(response.status_code, 404)
         data = response.json()
-        self.assertEqual(data["error"], "Senior Official not found")
+        self.assertEqual(data["error"], "Senior official not found")
diff --git a/src/registrar/views/utility/api_views.py b/src/registrar/views/utility/api_views.py
index 2c9414d1d..1e87e12e5 100644
--- a/src/registrar/views/utility/api_views.py
+++ b/src/registrar/views/utility/api_views.py
@@ -33,4 +33,4 @@ def get_senior_official_from_federal_agency_json(request):
 
         return JsonResponse(so_dict)
     else:
-        return JsonResponse({"error": "Senior Official not found"}, status=404)
+        return JsonResponse({"error": "Senior official not found"}, status=404)