diff --git a/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst b/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst
index 7e9ecccef1d7..2e50203b5347 100644
--- a/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst
+++ b/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst
@@ -626,6 +626,7 @@ Modem libraries
 
 * :ref:`nrf_modem_lib_readme` library:
 
+  * Updated the RTT trace backend to allocate the RTT channel at boot, instead of when the modem is activated.
   * Removed support for deprecated RAI socket options ``SO_RAI_LAST``, ``SO_RAI_NO_DATA``, ``SO_RAI_ONE_RESP``, ``SO_RAI_ONGOING``, and ``SO_RAI_WAIT_MORE``.
 
 Multiprotocol Service Layer libraries
diff --git a/lib/nrf_modem_lib/trace_backends/rtt/rtt.c b/lib/nrf_modem_lib/trace_backends/rtt/rtt.c
index 2cac78f6cd1d..c45ab81f130b 100644
--- a/lib/nrf_modem_lib/trace_backends/rtt/rtt.c
+++ b/lib/nrf_modem_lib/trace_backends/rtt/rtt.c
@@ -5,6 +5,7 @@
  */
 
 #include <stdio.h>
+#include <zephyr/init.h>
 #include <zephyr/logging/log.h>
 #include <modem/trace_backend.h>
 #include <SEGGER_RTT.h>
@@ -18,21 +19,15 @@ static trace_backend_processed_cb trace_processed_callback;
 
 int trace_backend_init(trace_backend_processed_cb trace_processed_cb)
 {
-	const int segger_rtt_mode = SEGGER_RTT_MODE_BLOCK_IF_FIFO_FULL;
-
 	if (trace_processed_cb == NULL) {
 		return -EFAULT;
 	}
-
-	trace_processed_callback = trace_processed_cb;
-
-	trace_rtt_channel = SEGGER_RTT_AllocUpBuffer("modem_trace", rtt_buffer, sizeof(rtt_buffer),
-						     segger_rtt_mode);
-
 	if (trace_rtt_channel <= 0) {
 		return -EBUSY;
 	}
 
+	trace_processed_callback = trace_processed_cb;
+
 	return 0;
 }
 
@@ -72,3 +67,18 @@ struct nrf_modem_lib_trace_backend trace_backend = {
 	.deinit = trace_backend_deinit,
 	.write = trace_backend_write,
 };
+
+/* Allocate RTT buffer ASAP so external tooling can attach before `nrf_modem_init` */
+IF_DISABLED(CONFIG_UNITY, (static))
+int nrf_modem_lib_trace_rtt_channel_alloc(void)
+{
+	const int segger_rtt_mode = SEGGER_RTT_MODE_BLOCK_IF_FIFO_FULL;
+
+	trace_rtt_channel = SEGGER_RTT_AllocUpBuffer("modem_trace", rtt_buffer, sizeof(rtt_buffer),
+						     segger_rtt_mode);
+
+	return trace_rtt_channel < 0 ? -EBUSY : 0;
+}
+
+/* The RTT core initialises in PRE_KERNEL_1 */
+SYS_INIT(nrf_modem_lib_trace_rtt_channel_alloc, POST_KERNEL, 0);
diff --git a/tests/lib/nrf_modem_lib/trace_backends/rtt/src/main.c b/tests/lib/nrf_modem_lib/trace_backends/rtt/src/main.c
index 4a32e78a7ad2..a7761145cc5f 100644
--- a/tests/lib/nrf_modem_lib/trace_backends/rtt/src/main.c
+++ b/tests/lib/nrf_modem_lib/trace_backends/rtt/src/main.c
@@ -10,6 +10,9 @@
 
 #include "trace_backend.h"
 
+/* SYS_INIT function */
+int nrf_modem_lib_trace_rtt_channel_alloc(void);
+
 extern struct nrf_modem_lib_trace_backend trace_backend;
 
 #include "cmock_SEGGER_RTT.h"
@@ -51,8 +54,10 @@ void test_trace_backend_init_rtt(void)
 	__cmock_SEGGER_RTT_AllocUpBuffer_ExpectAnyArgsAndReturn(trace_rtt_channel);
 	__cmock_SEGGER_RTT_AllocUpBuffer_AddCallback(&rtt_allocupbuffer_callback);
 
-	ret = trace_backend.init(callback);
+	ret = nrf_modem_lib_trace_rtt_channel_alloc();
+	TEST_ASSERT_EQUAL(0, ret);
 
+	ret = trace_backend.init(callback);
 	TEST_ASSERT_EQUAL(0, ret);
 }
 
@@ -63,6 +68,9 @@ void test_trace_backend_init_rtt_ebusy(void)
 	/* Simulate failure by returning negative RTT channel. */
 	__cmock_SEGGER_RTT_AllocUpBuffer_ExpectAnyArgsAndReturn(-1);
 
+	ret = nrf_modem_lib_trace_rtt_channel_alloc();
+	TEST_ASSERT_EQUAL(-EBUSY, ret);
+
 	ret = trace_backend.init(callback);
 	TEST_ASSERT_EQUAL(-EBUSY, ret);
 }