N⁶-methyladenosine (m⁶A) is the most abundant chemical modification in mRNA and plays important roles in human and mouse embryonic stem cell pluripotency, maintenance, and differentiation. We have recently reported that m⁶A is involved in the postnatal control of β-cell function in physiological states and in type 1 and 2 diabetes. However, the precise mechanisms by which m⁶A acts to regulate the development of human and mouse pancreas are unexplored. Here, we show that the m⁶A landscape is dynamic during human pancreas development, and that METTL14, one of the m⁶A writer complex proteins, is essential for the early differentiation of both human and mouse pancreatic cells.