The 29-year-old was released by Crystal Palace this summer and has signed a two-year contract, with an option for a third, to return to the club where he launched his professional career.
Campbell spent the 2007-08 season on loan at Hull from Manchester United, scoring 15 goals and setting up the memorable Dean Windass volley which secured victory in the Championship play-off final at Wembley – and promotion to the Premier League for the first time in the club’s history.
“I’m delighted to be a Tiger again and hopefully it can go the same way as it did last time with us winning promotion to the Premier League,” Campbell told the club’s official website.
“I’m looking forward to playing at the KCOM Stadium again and I can’t wait to get started.”
Campbell has also represented Sunderland and Cardiff, as well as a loan spell at Tottenham. He won one England cap as a substitute against Holland in February 2012.