Travis Kelce joins Taylor Swift on stage during a London concert

Taylor Swift thrilled fans with a surprise appearance from boyfriend Travis Kelce during the third Eras Tour performance at Wembley Stadium in London.

The Lover singer invited the Kansas City Chiefs star on to the stage as she performed I Can Do It With a Broken Heart.

WATCH THE VIDEO ABOVE: Travis Kelce appears with Taylor Swift at London concert.

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The crowd screamed when they saw the player, 34, approach his girlfriend and pick her up from a pretend faint.

Wearing a top hat and tails, the NFL player held Swift in his arms.

Taylor Swift is joined on stage by Travis Kelce in London on Saturday night. Credit: Gareth Cattermole/TAS24/Gareth Cattermole/Getty Images f

He then carried her to a red couch before fanning her next to two backup dancers.

The couple, who have been together since last year, appeared in their first social media photograph next to Prince William and his children Charlotte and George on Friday night.

Prince William, Charlotte and George pictured with Taylor Swift and boyfriend Travis Kelce at her London tour. Credit: Taylor Swift/supplied

They then sent fans into more of a frenzy with the unexpected Kelce moment at the concert, which was also attended by Sir Paul McCartney.

Kelce has made no secret of the fact he would like to join the entertainment industry.

In May, he announced he was “stepping into new territory” by taking on his first major acting role.

Kelce, who has found global fame as the boyfriend of Taylor Swift, will star in the upcoming series Grotesquerie by super-producer Ryan Murphy.

He will star opposite Niecy Nash-Betts, Courtney B Vance and British star Lesley Manville in the new horror drama, due to be released later this year.