The British singer, who played with Doncaster's reserve squad in February (14), is now the co-owner of his hometown team after his takeover bid with former club chairman John Ryan was officially accepted.
They have also set up The Tomlinson Ryan Trust to support and develop the team in the hope of turning their fortunes around after the Rovers were relegated to the third tier of English soccer in May (14).
Tomlinson and Ryan launched a money-raising campaign on Thursday (19Jun14) on Crowdfunder.co.uk and asked fans and football supporters to make pledges to help them reach a funding target of $3.2 million (£2 million).
The co-owners have agreed to donate a six-figure sum themselves.
The Trust aims to improve the financial future of the club, grow the brand, secure a top squad and ultimately reach the Premier League, the top level of English soccer.
Tomlinson says, "For me, this is all about the football, the community and restoring the excitement and desire to making Doncaster Rovers the most exciting club to play for in Yorkshire (in England).
"I grew up in Doncaster and have felt the love for football run through the town, it's for that reason that I have a real personal passion to make Doncaster Rovers a success story. I want to see the Doncaster Rovers' supporters get the club the success it deserves... This is a big step which I believe will open up opportunities to provide a very, very exciting future for the club and its supporters."
The pledge goal of $3.2 million must be met by 17 July (14).