MicroRNA (miR)‐203 is downregulated and acts as an anti‐oncomir in melanoma cells. Here, using human and canine melanoma cells, we elucidated the effects of miR‐203 on cyclic adenosine monophosphate response element binding protein (CREB)/microphthalmia‐associated transcription factor (MITF)/RAB27a pathway, which is known to be important for the development and progression of human melanoma. In this study, we showed that miR‐203 directly targeted CREB1 and regulated its downstream targets, MITF and RAB27a. miR‐203 significantly suppressed the growth of human and canine melanoma cells and inhibited melanosome transport through the suppression of the signalling pathway. In conclusion, miR‐203 was shown to be a common tumour‐suppressive miRNA in human and canine melanoma and thus to play a crucial role in the biological mechanisms of melanoma development.