Severin started his career at Heart of Midlothian. He was captain of the youth team that won the Scottish Youth Cup in 1998 under Peter Houston.[2] Severin made his debut as a substitute in Hearts' 3–1 victory over Dundee United on 6 April 1999, and his first starting appearance came three weeks later in a 4–0 win against Motherwell.[3][4] Severin started to play regularly for Hearts in the 1999–2000 season, making 28 appearances in all competitions and scoring his first professional goal in a Scottish League Cup match against Queen of the South. Hearts finished the season in third place, earning them qualification for the UEFA Cup and Severin's form earned him a new contract until 2004.[5] In his first ever continental match, Severin scored Hearts' first goal in their 2–0 UEFA Cup Qualifying victory over Icelandic side ÍBV.[6] Severin played once as a goalkeeper for Hearts, following an injury to Teuvo Moilanen.[citation needed]
In July 2004, Severin left Hearts on the expiration of his contract, and became Jimmy Calderwood's first signing at Aberdeen.[7] He signed a new three-and-a-half-year contract with Aberdeen in December 2005.[8] On the final day of the 2006–07 season, Severin scored in a victory against rivals Rangers which secured a UEFA Cup place for the following season.[9] In July 2007 he was handed the captaincy of Aberdeen, succeeding Russell Anderson.[10]
In June 2009 the Watford Observer reported he would be moving on a free transfer to Watford.[11] Watford later confirmed that he would sign on 1 July 2009.[12] Severin scored his first goal for Watford in a first round League Cup tie at Underhill Stadium against Barnet on 11 August 2009.[13] On 1 February 2010, he joined Kilmarnock on loan until the end of the 2009–10 season.[14] Severin made his first team debut for Kilmarnock a day later, as an 80th-minute substitute in a 1–0 Scottish Premier League win against Celtic.[15]
Severin transferred to Dundee United on 31 August 2010,[16] and scored his first goal for the club in a 4–2 win over Kilmarnock.[17] He suffered a triple leg break in a SPL match against St Mirren on 6 August 2011.[18] On 17 March 2012, Severin announced his retirement from professional football due to the injury he sustained against St Mirren.[19]
A. ^ Includes appearances in European competition.
B. ^ For the 2007/08 season, Soccerbase has not recorded Severin's appearance for Aberdeen away to Dnipro[23] in the UEFA Cup, so his European appearances for that season should be 8, not the 7 they have listed. Likewise with his overall total it should be one higher than they have listed.