diff --git a/p2p/base/port.cc b/p2p/base/port.cc
index 0d76614857..d3d2661e2c 100644
--- a/p2p/base/port.cc
+++ b/p2p/base/port.cc
@@ -89,15 +89,6 @@ absl::optional<ProtocolType> StringToProto(absl::string_view proto_name) {
   return absl::nullopt;
 }
 
-bool StringToProto(const char* value, ProtocolType* proto) {
-  if (absl::optional<ProtocolType> type = StringToProto(value);
-      type.has_value()) {
-    *proto = *type;
-    return true;
-  }
-  return false;
-}
-
 // RFC 6544, TCP candidate encoding rules.
 const int DISCARD_PORT = 9;
 const char TCPTYPE_ACTIVE_STR[] = "active";
diff --git a/p2p/base/port.h b/p2p/base/port.h
index dd7b3e3c02..6a5bdfcc9b 100644
--- a/p2p/base/port.h
+++ b/p2p/base/port.h
@@ -128,9 +128,6 @@ typedef std::vector<CandidateStats> CandidateStatsList;
 const char* ProtoToString(ProtocolType proto);
 absl::optional<ProtocolType> StringToProto(absl::string_view proto_name);
 
-// TODO(bugs.webrtc.org/13579): Delete once downstream usage is updated.
-[[deprecated]] bool StringToProto(const char* value, ProtocolType* proto);
-
 struct ProtocolAddress {
   rtc::SocketAddress address;
   ProtocolType proto;