diff --git a/p2p/base/async_stun_tcp_socket.cc b/p2p/base/async_stun_tcp_socket.cc
index 5f8f07227f..4a35903dfe 100644
--- a/p2p/base/async_stun_tcp_socket.cc
+++ b/p2p/base/async_stun_tcp_socket.cc
@@ -18,7 +18,6 @@
 #include "rtc_base/byte_order.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/network/sent_packet.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/time_utils.h"
 
 namespace cricket {
diff --git a/p2p/base/p2p_transport_channel.cc b/p2p/base/p2p_transport_channel.cc
index 17b59680e1..fe11920da9 100644
--- a/p2p/base/p2p_transport_channel.cc
+++ b/p2p/base/p2p_transport_channel.cc
@@ -43,7 +43,6 @@
 #include "rtc_base/network.h"
 #include "rtc_base/network_constants.h"
 #include "rtc_base/string_encode.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/time_utils.h"
 #include "rtc_base/trace_event.h"
 #include "system_wrappers/include/metrics.h"
diff --git a/p2p/base/p2p_transport_channel.h b/p2p/base/p2p_transport_channel.h
index dc27b202c2..1e0d1e339a 100644
--- a/p2p/base/p2p_transport_channel.h
+++ b/p2p/base/p2p_transport_channel.h
@@ -72,7 +72,6 @@
 #include "rtc_base/socket_address.h"
 #include "rtc_base/strings/string_builder.h"
 #include "rtc_base/system/rtc_export.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/thread.h"
 #include "rtc_base/thread_annotations.h"
 
diff --git a/p2p/base/tcp_port.cc b/p2p/base/tcp_port.cc
index fbda2999f9..2760c02819 100644
--- a/p2p/base/tcp_port.cc
+++ b/p2p/base/tcp_port.cc
@@ -82,7 +82,6 @@
 #include "rtc_base/logging.h"
 #include "rtc_base/net_helper.h"
 #include "rtc_base/rate_tracker.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 
 namespace cricket {
 using ::webrtc::SafeTask;
diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index 1f830072f3..d63d98e483 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -139,7 +139,6 @@ rtc_source_set("dtls_srtp_transport") {
     "../rtc_base:checks",
     "../rtc_base:logging",
     "../rtc_base:ssl",
-    "../rtc_base/third_party/sigslot",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
 }
@@ -1250,7 +1249,6 @@ rtc_source_set("peer_connection") {
     "../rtc_base:threading",
     "../rtc_base:unique_id_generator",
     "../rtc_base:weak_ptr",
-    "../rtc_base/third_party/sigslot",
     "../system_wrappers:metrics",
   ]
   absl_deps = [
@@ -1661,7 +1659,6 @@ rtc_library("rtp_transmission_manager") {
     "../rtc_base:ssl",
     "../rtc_base:threading",
     "../rtc_base:weak_ptr",
-    "../rtc_base/third_party/sigslot",
   ]
   absl_deps = [
     "//third_party/abseil-cpp/absl/algorithm:container",
diff --git a/pc/dtls_srtp_transport.h b/pc/dtls_srtp_transport.h
index 7958210c99..0f8338ca0d 100644
--- a/pc/dtls_srtp_transport.h
+++ b/pc/dtls_srtp_transport.h
@@ -23,7 +23,6 @@
 #include "p2p/base/packet_transport_internal.h"
 #include "pc/srtp_transport.h"
 #include "rtc_base/buffer.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 
 namespace webrtc {
 
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 224148d16e..db26b5072a 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -1329,7 +1329,6 @@ rtc_library("async_tcp_socket") {
     ":timeutils",
     "../api:array_view",
     "network:sent_packet",
-    "third_party/sigslot",
   ]
 }
 
@@ -1352,7 +1351,6 @@ rtc_library("async_udp_socket") {
     "../system_wrappers:field_trial",
     "network:sent_packet",
     "system:no_unique_address",
-    "third_party/sigslot",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
 }
diff --git a/rtc_base/async_tcp_socket.cc b/rtc_base/async_tcp_socket.cc
index 97e8611fe2..367c5b04e7 100644
--- a/rtc_base/async_tcp_socket.cc
+++ b/rtc_base/async_tcp_socket.cc
@@ -21,7 +21,6 @@
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/network/sent_packet.h"
-#include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/time_utils.h"  // for TimeMillis
 
 #if defined(WEBRTC_POSIX)