diff --git a/arch/arm/src/imxrt/Kconfig b/arch/arm/src/imxrt/Kconfig
index 44807a062ee..22396545ef8 100644
--- a/arch/arm/src/imxrt/Kconfig
+++ b/arch/arm/src/imxrt/Kconfig
@@ -2633,7 +2633,17 @@ config IMXRT_DTCM_HEAP
 	bool "Add DTCM to heap"
 	depends on IMXRT_DTCM > 0
 	---help---
-		Select to add the entire DTCM to the heap
+		Select to add the DTCM to the heap
+
+config IMXRT_DTCM_HEAP_SIZE
+	int "DTCM heap Size in K"
+	depends on IMXRT_DTCM_HEAP
+	default IMXRT_DTCM
+	---help---
+		By default, the full configured DTCM region is assigned to the heap for
+		dynamic allocation. In scenarios requiring deterministic memory regions
+		for static buffers or control structures, you can reduce the heap
+		allocation to reserve part of DTCM for manual/static use.
 
 config IMXRT_BOOTLOADER_HEAP
 	bool "Add ROM bootloader 40Kib RAM to heap"
diff --git a/arch/arm/src/imxrt/imxrt_allocateheap.c b/arch/arm/src/imxrt/imxrt_allocateheap.c
index 307bf4fba62..8ae3c9a7263 100644
--- a/arch/arm/src/imxrt/imxrt_allocateheap.c
+++ b/arch/arm/src/imxrt/imxrt_allocateheap.c
@@ -203,7 +203,7 @@ extern  const uint32_t  _ram_size[];  /* See linker script */
 #  define IMXRT_OCRAM_ASSIGNED 1
 #elif defined(CONFIG_IMXRT_DTCM_HEAP) && !defined(IMXRT_DCTM_ASSIGNED)
 #  define REGION1_RAM_START    IMXRT_DTCM_BASE
-#  define REGION1_RAM_SIZE     CONFIG_DTCM_USED
+#  define REGION1_RAM_SIZE     (CONFIG_IMXRT_DTCM_HEAP_SIZE * 1024)
 #  define IMXRT_DCTM_ASSIGNED 1
 #elif defined(CONFIG_IMXRT_SDRAM_HEAP) && !defined(IMXRT_SDRAM_ASSIGNED)
 #  define REGION1_RAM_START    (CONFIG_IMXRT_SDRAM_START + CONFIG_IMXRT_SDRAM_HEAPOFFSET)