diff --git a/Octokit.Tests.Integration/Clients/RepositoryCommitsClientTests.cs b/Octokit.Tests.Integration/Clients/RepositoryCommitsClientTests.cs
index 95464917..7724e443 100644
--- a/Octokit.Tests.Integration/Clients/RepositoryCommitsClientTests.cs
+++ b/Octokit.Tests.Integration/Clients/RepositoryCommitsClientTests.cs
@@ -87,6 +87,14 @@ public class RepositoryCommitsClientTests
                 .Where(file => file.Status == "renamed")
                 .All(file => string.IsNullOrEmpty(file.PreviousFileName) == false));
         }
+
+        [IntegrationTest]
+        public async Task CanGetSha1()
+        {
+            var sha1 = await _fixture.Sha1("octokit", "octokit.net", "master");
+
+            Assert.NotNull(sha1);
+        }
     }
 
     public class TestsWithNewRepository : IDisposable
diff --git a/Octokit.Tests/Clients/RepositoriesClientTests.cs b/Octokit.Tests/Clients/RepositoriesClientTests.cs
index e74cc97b..e1130eac 100644
--- a/Octokit.Tests/Clients/RepositoriesClientTests.cs
+++ b/Octokit.Tests/Clients/RepositoriesClientTests.cs
@@ -790,5 +790,35 @@ namespace Octokit.Tests.Clients
                 await Assert.ThrowsAsync<ArgumentException>(() => client.EditBranch("owner", "repo", "", update));
             }
         }
+
+        public class TheSha1Method
+        {
+            [Fact]
+            public async Task EnsureNonNullArguments()
+            {
+                var client = new RepositoryCommitsClient(Substitute.For<IApiConnection>());
+
+                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Sha1(null, "name", "reference"));
+                await Assert.ThrowsAsync<ArgumentException>(() => client.Sha1("", "name", "reference"));
+
+                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Sha1("owner", null, "reference"));
+                await Assert.ThrowsAsync<ArgumentException>(() => client.Sha1("owner", "", "reference"));
+
+                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Sha1("owner", "name", null));
+                await Assert.ThrowsAsync<ArgumentException>(() => client.Sha1("owner", "name", ""));
+            }
+
+            [Fact]
+            public void GetsCorrectUrl()
+            {
+                var connection = Substitute.For<IApiConnection>();
+                var client = new RepositoryCommitsClient(connection);
+
+                client.Sha1("owner", "name", "reference");
+
+                connection.Received()
+                    .Get<string>(Arg.Is<Uri>(u => u.ToString() == "repos/owner/name/commits/reference"), null, AcceptHeaders.CommitReferenceSha1Preview);
+            }
+        }
     }
 }
diff --git a/Octokit/Clients/IRepositoryCommitsClient.cs b/Octokit/Clients/IRepositoryCommitsClient.cs
index f2b09f2b..27b846cb 100644
--- a/Octokit/Clients/IRepositoryCommitsClient.cs
+++ b/Octokit/Clients/IRepositoryCommitsClient.cs
@@ -50,5 +50,14 @@ namespace Octokit
         /// <param name="request">Used to filter list of commits returned</param>
         /// <returns></returns>
         Task<IReadOnlyList<GitHubCommit>> GetAll(string owner, string name, CommitRequest request);
+
+        /// <summary>
+        /// Get the SHA-1 of a commit reference
+        /// </summary>
+        /// <param name="owner">The owner of the repository</param>
+        /// <param name="name">The name of the repository</param>
+        /// <param name="reference">The repository reference</param>
+        /// <returns></returns>
+        Task<string> Sha1(string owner, string name, string reference);
     }
 }
diff --git a/Octokit/Clients/RepositoryCommitsClient.cs b/Octokit/Clients/RepositoryCommitsClient.cs
index 0e8ad1b2..c328cfb6 100644
--- a/Octokit/Clients/RepositoryCommitsClient.cs
+++ b/Octokit/Clients/RepositoryCommitsClient.cs
@@ -79,5 +79,21 @@ namespace Octokit
             return _apiConnection.GetAll<GitHubCommit>(ApiUrls.RepositoryCommits(owner, name),
                 request.ToParametersDictionary());
         }
+
+        /// <summary>
+        /// Get the SHA-1 of a commit reference
+        /// </summary>
+        /// <param name="owner">The owner of the repository</param>
+        /// <param name="name">The name of the repository</param>
+        /// <param name="reference">The repository reference</param>
+        /// <returns></returns>
+        public Task<string> Sha1(string owner, string name, string reference)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
+            Ensure.ArgumentNotNullOrEmptyString(name, "name");
+            Ensure.ArgumentNotNullOrEmptyString(reference, "reference");
+
+            return _apiConnection.Get<string>(ApiUrls.RepositoryCommit(owner, name, reference), null, AcceptHeaders.CommitReferenceSha1Preview);
+        }
     }
 }
\ No newline at end of file