
Faircliff will hold the role until March next year. Reay's term expires this October.
Both take over the role previously held by Simon Waldman, director of digital publishing at Guardian Media Group.
Waldman has now formally stepped down from the role.
The AOP said the joint, overlapping chairmanships allow greater rotation in the role of representatives drawn from newspapers, magazines, broadcasters and online-only players, to reflect the AOP's diverse membership.
Faircliff leads the sales, marketing and development of Thomson Reuters' multimedia news and information products available on digital media platforms, including Reuters.com, mobile applications, and internet delivered television.
Faircliff said: "Reuters has long supported AOP's focused and varied efforts on behalf of online publishing."