Full-back Marc Tierney joined Norwich City from Colchester on 13th January 2010 for an undisclosed fee, signing a two and a half year contract. He will provide competition to Adam Drury and Steven Smith for the left-back position.

Tierney rose through the youth ranks at Oldham Athletic, making his professional debut for Oldham in a Carling Cup match in August of the 2003–04 season, against Scunthorpe United. In December 2004 he went to Carlisle United on loan for a three month spell under Paul Simpson.

In January 2007, Tierney was signed by Shrewsbury Town in a two and a half year deal. He was a regular in the Shrewsbury side during the closing months of the 2006–07 season, as Town reached the League Two playoff final at Wembley. Notably, Tierney was sent off in the dying minutes of that game, making him only the second player to suffer this fate at the new stadium

In spite of Shrewsbury's disappointing 2007–08 season, Tierney enjoyed excellent personal form. His consistently dependable performances earned him both the fans' and players' player of the year awards

On November 27, 2008 Tierney joined Colchester United on an initial five-week loan. The move was made permanent by manager Paul Lambert in the January 2009 transfer window. He made 74 appearances for the U's before joining Norwich, scoring once.

At the end of his first season, Norwich won promotion to the Premiership, on 2nd May 2011 with a 1-0 win at Portsmouth with Marc playing a key role (16 appearances) in the Canaries' promotion challenge. He was also linked with a call up to the Irish squad

Impressive form in Norwich's opening start to the 2011/12 premier League season saw Tierney linked again withthe Irish squad, with Irish coach Marco Tardelli revealing that that Norwich City trio Wes Hoolahan, Anthony Pilkington and Marc Tierney are firmly on his international radar ahead of the Euro 2012 finals. The former World Cup winner, who was at Carrow Road to see the Canaries take on Arsenal, admitted he and Ireland manager Giovanni Trapattoni were weighing up all their options with regards to their final 23-man Euro2012 squad.

Tierney made 17 appearances during the 2011/12 Premier League season but missed the second half through injury.