Sextuplet depart Portsmouth
Davis, 29, signed a three-year deal with Bolton and joins on a free transfer just six months after Portsmouth rejected a 3.5 million pounds bid from Gary Megson's side.
"We made Sean the best offer we could and he declined it. There's nothing more that we could do," Portsmouth executive chairman Peter Storrie told the club website.
Defenders Noe Paramot, Lauren, Djimi Traore and midfielders Glen Little and Jerome Thomas have been released by the club after their contracts expired.
Portsmouth, 2008 FA Cup winners, said Nigerian striker Nwankwo Kanu is considering a new one-year deal, while the club will decide next week whether to begin discussions with out-of-contract defender Sol Campbell.