diff --git a/thriftbp/client_pool.go b/thriftbp/client_pool.go
index 1f307d921..27a66efb9 100644
--- a/thriftbp/client_pool.go
+++ b/thriftbp/client_pool.go
@@ -211,6 +211,11 @@ type ClientPoolConfig struct {
 	//
 	// Optional. If this is empty, no "User-Agent" header will be sent.
 	ClientName string `yaml:"clientName"`
+
+	// The hostname to add as a "thrift-hostname" header.
+	//
+	// Optional. If empty, no "thrift-hostname" header will be sent.
+	ThriftHostnameHeader string `yaml:"thriftHostnameHeader"`
 }
 
 // Validate checks ClientPoolConfig for any missing or erroneous values.
@@ -429,6 +434,24 @@ func NewCustomClientPoolWithContext(
 	return newClientPool(ctx, cfg, genAddr, protoFactory, middlewares...)
 }
 
+const ThriftHostnameHeader = "thrift-hostname"
+
+// thriftHostnameHeaderMiddleware adds a `thrift-hostname` header if one was
+// specified in the configuration.
+// This middleware is always added but will only add the header is necessary.
+func thriftHostnameHeaderMiddleware(hostname string) thrift.ClientMiddleware {
+	return func(next thrift.TClient) thrift.TClient {
+		return thrift.WrappedTClient{
+			Wrapped: func(ctx context.Context, method string, args, result thrift.TStruct) (thrift.ResponseMeta, error) {
+				if hostname != "" {
+					ctx = AddClientHeader(ctx, ThriftHostnameHeader, hostname)
+				}
+				return next.Call(ctx, method, args, result)
+			},
+		}
+	}
+}
+
 func newClientPool(
 	ctx context.Context,
 	cfg ClientPoolConfig,
@@ -505,6 +528,8 @@ func newClientPool(
 
 		slug: cfg.ServiceSlug,
 	}
+	middlewares = append(middlewares, thriftHostnameHeaderMiddleware(cfg.ThriftHostnameHeader))
+
 	// finish setting up the clientPool by wrapping the inner "Call" with the
 	// given middleware.
 	//
diff --git a/thriftbp/client_pool_test.go b/thriftbp/client_pool_test.go
index 71e0de803..f31b09e6e 100644
--- a/thriftbp/client_pool_test.go
+++ b/thriftbp/client_pool_test.go
@@ -11,8 +11,11 @@ import (
 
 	"github.com/apache/thrift/lib/go/thrift"
 
+	"github.com/reddit/baseplate.go"
 	"github.com/reddit/baseplate.go/ecinterface"
+	baseplatethrift "github.com/reddit/baseplate.go/internal/gen-go/reddit/baseplate"
 	"github.com/reddit/baseplate.go/thriftbp"
+	"github.com/reddit/baseplate.go/thriftbp/thrifttest"
 )
 
 const (
@@ -190,6 +193,49 @@ func TestBehaviorWithNetworkIssues(t *testing.T) {
 	}
 }
 
+type thriftHostnameHandler struct {
+	server baseplate.Server
+}
+
+func (thriftHostnameHandler) IsHealthy(ctx context.Context, _ *baseplatethrift.IsHealthyRequest) (r bool, err error) {
+	value, ok := thrift.GetHeader(ctx, thriftbp.ThriftHostnameHeader)
+	if !ok {
+		return false, errors.New("did not find the thrift header")
+	}
+	if value != "my-thrift-header" {
+		return false, errors.New("unexpected value for the thrift header")
+	}
+	return true, nil
+}
+
+func TestThriftHostnameHeader(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	store := newSecretsStore(t)
+	defer store.Close()
+
+	handler := thriftHostnameHandler{}
+	server, err := thrifttest.NewBaseplateServer(thrifttest.ServerConfig{
+		Processor:   baseplatethrift.NewBaseplateServiceV2Processor(&handler),
+		SecretStore: store,
+		ClientConfig: thriftbp.ClientPoolConfig{
+			ThriftHostnameHeader: "my-thrift-header",
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	handler.server = server
+	server.Start(ctx)
+
+	client := baseplatethrift.NewBaseplateServiceV2Client(server.ClientPool.TClient())
+	_, err = client.IsHealthy(ctx, &baseplatethrift.IsHealthyRequest{})
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestInitialConnectionsFallback(t *testing.T) {
 	ln, err := net.Listen("tcp", addr)
 	if err != nil {