Norwood moves to Brighton
Norwood, who began his career at Old Trafford and went on to sign for Huddersfield Town following loan spells at Carlisle, Scunthorpe and Coventry, started every game for Northern Ireland as they reached the knockout stages of the European Championship finals in France this summer.
Norwood was brought to Berkshire by Nigel Adkins and was preparing to enter the last year of his contract at the club.
He made his Royals bow when he came off the bench to replace Jake Taylor in a defeat at Nottingham Forest and then scored his first league goal at Rotherham towards the end of that same Championship campaign.
Seagulls boss Chris Hughton said: “Oliver is another excellent addition to our squad.
“He has a good grounding coming from Manchester United and has a wealth of experience playing in the Championship and at international level.
“He’s a box-to-box player and an excellent passer of the ball, so he gives us extra options in midfield and adds further depth to our squad.”
Norwood joins Steve Sidwell, who turned his loan spell from Stoke City in to a permanent move, Ben Hall and Glenn Murray, who has moved to the AMEX Stadium on loan from Premier League side Bournemouth.
Albion accumulated 89 points in the Sky Bet Championship last season, missing out on promotion to the Premier League on goal difference in a final day showdown with Middlesbrough at the Riverside.
They then bowed out of the play-offs to Sheffield Wednesday.
Norwood could make his debut for his new employers tomorrow as they kick off their campaign against Derby County at the iPro Stadium.