The former Arsenal, Coventry, Perugia, Blackburn, Charlton, Stoke and Wolves player, 26, has signed a three year deal with the Bluebirds.
Bothroyd watched the 0 - 0 draw with Ajax from the Ninian Park stands and thankfully this time decided to sign on the dotted line unlike Bent and Fowler who's heads were turned by other clubs.
"I am excited at the prospect of pulling on a Bluebirds' shirt," said Bothroyd.
"I know from past experience the support and passion this club can command - and I can't wait to run out in front of the City fans.
"Cardiff are an ambitious club and I am delighted to have signed. I am impressed by the plans laid out by the manager and chairman."
Bothroyd becomes manager Dave Jones' seventh summer signing, following Tom Heaton, Peter Enckelman (who was on loan last season), Miguel Comminges, Mark Kennedy, Darren Dennehy and Ross McCormack to Ninian Park.