LONDON—Central banks should consider joining forces to create a virtual currency that could supplant the dollar’s role in the global economy, Bank of England Gov. Mark Carney said, offering a novel solution to concerns about the greenback’s status as the world’s foremost reserve currency.

In a speech Friday to an annual gathering of central bankers in Jackson Hole, Wyo., Mr. Carney said the dollar’s “domineering” place in world trade and the global financial system creates problems for policy makers outside the U.S. in managing...