The 25-year-old has put pen to paper on a contract which will keep him at the KCOM Stadium until 2020, with the option of an extra year on top of that.
Dicko, who scored 31 goals in 96 league appearances for Wolves, revealed that the prospect of a move materialised after he scored against the Tigers earlier this month.
"I am really happy to be here and hopefully it is going to be a good time for the club and for me," he told the club's official website.
"It's a move that has been on the cards for a couple of weeks, ever since Wolves played Hull up here. I found out that Hull City were interested in signing me and things started moving from there. I'm glad that everything is sorted now and I'm looking forward to settling down here and getting started."
Dicko could make his debut for Hull when they take on Derby County after the international break.