London's mayor has been spotted holidaying in far north Queensland.

Surprised English tourists nabbed a photo of a relaxed looking Boris Johnson while visiting an indigenous cultural centre north of Cairns.

The Mossman Gorge Centre offers guided walks and runs a popular bus service to numerous swimming holes along the gorge.

The Hartley family from Blackpool said Mr Johnson was more than happy to pose for a photo.

"Surprise / pleasure to meet @MayorofLondon at Mossman Gorge Oz today," they Tweeted alongside a photo on Tuesday.

Staff at the centre said they hadn't seen the elusive mayor.

A spokeswoman from the Cairns Regional Council says staff weren't aware Cr Johnson was holidaying in the area.