The 38-year-old former Manchester United and West Ham player joins the Blues after a spell with Notts County.
Carroll, who has won 42 international caps, will link up with former Northern Ireland team-mate and current Linfield boss David Healy.
"He's obviously a player I know very well and he will bring with him considerable experience," said Healy.
Carroll made his Northern Ireland debut against Thailand in 1997 and is expected to be in the squad for the Euro 2016 finals in France.
Linfield finished second in the league last season and were beaten in the Irish Cup final by Glenavon.
"His experience will be of enormous benefit to the goalkeepers and indeed our entire squad," added Healy.
"I'm looking forward to working with him once his international commitments are concluded in the coming weeks."
Northern Ireland goalkeeper Roy Carroll has signed for Premiership club Linfield on a one-year deal.