The 22-year-old has signed a four-year contract at Portman Road after failing to make the grade at Old Trafford and is Keane's third signing of the summer.

Martin has enjoyed loan spells at Rangers, Stoke, Plymouth, Sheffield United and Nottingham Forest and made three appearances for United.

He said: "It obviously wasn't an easy decision to leave a club like Manchester United but I know how ambitious the manager is here and I'm delighted to be a part of his plans for the future.

"It's also important for me to be playing regular first-team football and hopefully I can help Ipswich get back in the Premier League."