The boy band star signed up to play a game for English football club Doncaster, a team that plays in the second-tier League Championship.
The announcement — labelled "breaking news" by Britain's 24-hour sports news channel — will see Tomlinson given the No. 28 shirt in his club's squad.
"This has always been a childhood dream for me," the 21-year-old Tomlinson said. "I feel very honoured to have been asked to sign for Rovers."
Before finding global fame after One Direction placed third on the British version of "The X Factor" in 2010, Tomlinson did part time work at Doncaster's stadium, serving food.
But he always hoped to pull on the shirt of his hometown club in northern England one day.
"We often play football with the lads, any time we get," Tomlinson said. "Sometimes we might be on the road and just pull over at 3 a.m. at a local service station and just have a bit of a kickaround."
But One Directioners shouldn't worry about not seeing the group performing as a quintet again. Tomlinson reassured fans he's not leaving the band and is only likely to play in a reserve team game in September or October to raise money for a children's hospice.
"He's missed pre-season training already," Doncaster manager Paul Dickov quipped on Sky Sports TV.