diff --git a/tests/bsim/bluetooth/ll/compile.sh b/tests/bsim/bluetooth/ll/compile.sh
index 4937c72951d..5b7e374510a 100755
--- a/tests/bsim/bluetooth/ll/compile.sh
+++ b/tests/bsim/bluetooth/ll/compile.sh
@@ -17,6 +17,7 @@ app=tests/bsim/bluetooth/ll/advx \
   conf_overlay=overlay-ticker_expire_info.conf compile
 
 app=tests/bsim/bluetooth/ll/conn conf_file=prj_split.conf compile
+app=tests/bsim/bluetooth/ll/conn conf_file=prj_split_1ms.conf compile
 app=tests/bsim/bluetooth/ll/conn conf_file=prj_split_tx_defer.conf compile
 app=tests/bsim/bluetooth/ll/conn conf_file=prj_split_privacy.conf compile
 app=tests/bsim/bluetooth/ll/conn conf_file=prj_split_low_lat.conf compile
diff --git a/tests/bsim/bluetooth/ll/conn/Kconfig b/tests/bsim/bluetooth/ll/conn/Kconfig
new file mode 100644
index 00000000000..87a403f2d7d
--- /dev/null
+++ b/tests/bsim/bluetooth/ll/conn/Kconfig
@@ -0,0 +1,11 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config TEST_CONN_INTERVAL_1MS
+	bool "Test 1 ms connection interval support"
+	help
+	  Test 1 ms connection interval support.
+
+menu "Zephyr Kernel"
+source "Kconfig.zephyr"
+endmenu
diff --git a/tests/bsim/bluetooth/ll/conn/prj_split_1ms.conf b/tests/bsim/bluetooth/ll/conn/prj_split_1ms.conf
new file mode 100644
index 00000000000..58276bd991e
--- /dev/null
+++ b/tests/bsim/bluetooth/ll/conn/prj_split_1ms.conf
@@ -0,0 +1,23 @@
+CONFIG_BT=y
+CONFIG_LOG=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_PRIVACY=y
+CONFIG_BT_SMP=y
+CONFIG_BT_SIGNING=y
+CONFIG_BT_BAS=y
+CONFIG_BT_HRS=y
+CONFIG_BT_ATT_PREPARE_COUNT=2
+CONFIG_BT_GATT_CLIENT=y
+CONFIG_BT_L2CAP_DYNAMIC_CHANNEL=y
+CONFIG_BT_DEVICE_NAME="bsim_test_split_1m"
+CONFIG_BT_L2CAP_TX_BUF_COUNT=6
+
+CONFIG_BT_CTLR_PRIVACY=n
+
+CONFIG_BT_CONN_PARAM_ANY=y
+
+CONFIG_BT_CTLR_ADVANCED_FEATURES=y
+CONFIG_BT_CTLR_CONN_INTERVAL_LOW_LATENCY=y
+
+CONFIG_TEST_CONN_INTERVAL_1MS=y
diff --git a/tests/bsim/bluetooth/ll/conn/src/test_connect1.c b/tests/bsim/bluetooth/ll/conn/src/test_connect1.c
index d1373084da5..a31ff3d0d9a 100644
--- a/tests/bsim/bluetooth/ll/conn/src/test_connect1.c
+++ b/tests/bsim/bluetooth/ll/conn/src/test_connect1.c
@@ -29,10 +29,19 @@ static struct bt_uuid_16 uuid = BT_UUID_INIT_16(0);
 static struct bt_gatt_discover_params discover_params;
 static struct bt_gatt_subscribe_params subscribe_params;
 
+#if defined(CONFIG_TEST_CONN_INTERVAL_1MS)
+#define UPDATE_PARAM_INTERVAL_MIN 1
+#define UPDATE_PARAM_INTERVAL_MAX 1
+#define UPDATE_PARAM_LATENCY      0
+#define UPDATE_PARAM_TIMEOUT      10
+#define TEST_NOTIFY_COUNT         3000
+#else /* !CONFIG_TEST_CONN_INTERVAL_1MS */
 #define UPDATE_PARAM_INTERVAL_MIN 25
 #define UPDATE_PARAM_INTERVAL_MAX 45
 #define UPDATE_PARAM_LATENCY      1
 #define UPDATE_PARAM_TIMEOUT      250
+#define TEST_NOTIFY_COUNT         3
+#endif /* !CONFIG_TEST_CONN_INTERVAL_1MS */
 
 static struct bt_le_conn_param update_params = {
 	.interval_min = UPDATE_PARAM_INTERVAL_MIN,
@@ -124,16 +133,32 @@ static uint8_t notify_func(struct bt_conn *conn,
 			struct bt_gatt_subscribe_params *params,
 			const void *data, uint16_t length)
 {
+	static uint32_t cycle_stamp;
 	static int notify_count;
+	uint32_t cycle_now;
+	uint64_t delta;
+
 	if (!data) {
 		printk("[UNSUBSCRIBED]\n");
 		params->value_handle = 0U;
 		return BT_GATT_ITER_STOP;
 	}
 
-	printk("[NOTIFICATION] data %p length %u\n", data, length);
+	cycle_now = k_cycle_get_32();
+	delta = cycle_now - cycle_stamp;
+	cycle_stamp = cycle_now;
+	delta = k_cyc_to_ns_floor64(delta);
+
+	if (!IS_ENABLED(CONFIG_TEST_CONN_INTERVAL_1MS) ||
+	    ((delta > (NSEC_PER_MSEC / 2U)) &&
+	     (delta < (NSEC_PER_MSEC + (NSEC_PER_MSEC / 2U))))) {
+		notify_count++;
+	}
+
+	printk("[NOTIFICATION] %u. data %p length %u in %llu ns\n",
+	       notify_count, data, length, delta);
 
-	if (notify_count++ >= 1) { /* We consider it passed */
+	if (notify_count >= TEST_NOTIFY_COUNT) { /* We consider it passed */
 		int err;
 
 		/* Disconnect before actually passing */
diff --git a/tests/bsim/bluetooth/ll/conn/src/test_connect2.c b/tests/bsim/bluetooth/ll/conn/src/test_connect2.c
index 54551f01b50..f648d2d2d90 100644
--- a/tests/bsim/bluetooth/ll/conn/src/test_connect2.c
+++ b/tests/bsim/bluetooth/ll/conn/src/test_connect2.c
@@ -209,7 +209,8 @@ static void test_con2_main(void)
 	 * of starting delayed work so we do it here
 	 */
 	while (1) {
-		if (IS_ENABLED(CONFIG_BT_CTLR_TX_DEFER)) {
+		if (IS_ENABLED(CONFIG_TEST_CONN_INTERVAL_1MS) ||
+		    IS_ENABLED(CONFIG_BT_CTLR_TX_DEFER)) {
 			k_sleep(K_MSEC(1));
 		} else {
 			k_sleep(K_SECONDS(1));
diff --git a/tests/bsim/bluetooth/ll/conn/tests_scripts/basic_conn_split_1ms.sh b/tests/bsim/bluetooth/ll/conn/tests_scripts/basic_conn_split_1ms.sh
new file mode 100755
index 00000000000..0be845f12d6
--- /dev/null
+++ b/tests/bsim/bluetooth/ll/conn/tests_scripts/basic_conn_split_1ms.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# Copyright 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+# Basic connection test: a central connects to a peripheral and expects a
+# notification, using the split controller (ULL LLL) and 1ms connection
+# interval
+simulation_id="basic_conn_split_1ms"
+verbosity_level=2
+
+cd ${BSIM_OUT_PATH}/bin
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_ll_conn_prj_split_1ms_conf \
+  -v=${verbosity_level} -s=${simulation_id} -d=0 -RealEncryption=1 \
+  -testid=peripheral -rs=23
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_ll_conn_prj_split_1ms_conf\
+  -v=${verbosity_level} -s=${simulation_id} -d=1 -RealEncryption=1 \
+  -testid=central -rs=6
+
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} \
+  -D=2 -sim_length=20e6 $@
+
+wait_for_background_jobs