Darren O'Dea

Born in Dublin, O'Dea played for Home Farm before he was signed by Celtic as a teenager. After making his way through the reserves and academy side, he made his first-team debut for Celtic in the Scottish League Cup against St Mirren in September 2006. A month later, O'Dea made his league debut against Inverness Caledonian Thistle, where he played the last thirty minutes after substituting for Gary Caldwell. His UEFA Champions League debut was on 6 December against Danish club F.C. Copenhagen as a substitute for the injured Stephen McManus. O'Dea made his first league starting appearance against Dunfermline Athletic four days after his Champions League debut. Later that month he scored his first goal in a match against Dundee United, with his rebound of a 78th-minute free kick by Shunsuke Nakamura tying the match 2–2. O'Dea's first season saw him also score against Livingston in the run to the 2006–07 Scottish Cup.

After playing 16 times for Celtic, O'Dea signed a three-year contract in March 2007 and considered it a "reward for the hard work" he had done. In his second season he contributed to Celtic winning the league championship, although he did not feature in the title winning match against Dundee United. After O'Dea did not play for two months (since his last Champions League match against FC Spartak Moscow), the BBC reported in October that he would be recalled to the injury-plagued team as a replacement for Gary Caldwell, and he played the entire league match against Rangers on 20 October 2007. That season, he primarily played centre-back.

After playing for the Irish under-19 and under-21 teams, O'Dea was called up to the international squad within a year. Promoted to the Irish under-21 international squad by manager Don Givens on 3 March 2007, he was the team captain. Less than a week later, O'Dea was named to the international squad for Ireland's UEFA Euro 2008 qualifying Group D matches on 24 and 28 March.

On 13 May 2008, he was listed on Giovanni Trapattoni's first squad as Ireland's manager for the 2010 FIFA World Cup qualification – UEFA Group 8 matches against Bulgaria and Italy. O'Dea made his senior-team debut on 8 September 2009 in a 1–0 friendly win over South Africa at Thomond Park in Limerick as a 60th-minute substitute for Paul McShane.

During the 2008–09 season O'Dea made a total of sixteen appearances, scoring twice. His extra-time goal in the 2009 Scottish League Cup Final gave Celtic the trophy. After playing fifty times for the club, O'Dea was loaned to championship club Reading in September 2009 for more first-team experience and he called it a "massive chance" to represent Celtic. He made his debut in a 0–0 draw against Doncaster Rovers, with his second-half shot saved by Doncaster goalkeeper Neil Sullivan. In a September interview, O'Dea was reluctant to return to Celtic for rare match opportunities.

Returning from Reading in January 2010, he started all five games that month. O'Dea was appointed stand-in captain after Stephen McManus went on loan to Middlesbrough and Gary Caldwell left for Wigan. At the start of the following season, again finding himself superfluous at Celtic, he was loaned to Ipswich Town on 18 August 2010 until January 2011 and made his Ipswich debut against Crystal Palace on 21 August. In January O'Dea said he was uncertain if his loan would be extended because of the sacking of Ipswich manager Roy Keane, expressing his desire to stay. New manager Paul Jewell unexpectedly extended his loan to the end of the season. Vital Football praised O'Dea's performance in a league cup match against Arsenal, with Jewell calling it "tremendous and crucial in the result". Two months later, he expressed a desire to return to Celtic instead of signing permanently with Ipswich. O'Dea said he would play for another club if he did not have first-team opportunities at Celtic, since he felt that playing was "not about sitting on a bench".

In May 2011, he said he "may quit Celtic" to play regularly and represent the national team at the 2012 UEFA Euro qualifiers. The following month Leeds United signed him on loan until the end of the season, and he said his objective on his new club was to win promotion to Premier League. O'Dea made his Leeds debut in a 3–1 loss to Southampton. He scored his first goal for the club against Coventry City, an "angled shot" for a 1–1 draw. O'Dea again found the net in the next game, against Peterborough United, in the 95th minute for a 3–2 win. Against Cardiff City, according to the BBC Leeds conceded a goal due to O'Dea's "indecision" which "opened the door for Joe Mason". In a January 2012 interview he expressed his desire to sign permanently with Leeds, although he received a red card in a loss to Blackpool. O'Dea played 38 times for Leeds, scoring twice. Due to his form with Leeds and Ireland, O'Dea and teammate Aidy White were nominated for the Young International Player of the Year at the Football Association of Ireland International Football Awards. He won the award in a ceremony held in February 2012.

After spending the previous two seasons out on loan, O'Dea was released by Celtic at the end of his contract on 1 June 2012 despite a one-year contract-extension option. He said he "had a great time at Celtic and have a lot of friends there so it was important for me that I left properly".

O'Dea signed with Major League Soccer club Toronto FC on 3 August 2012, and made his club debut on 18 August in a 1–0 home loss to Sporting Kansas City. According to CBC News, he looked "lively" in his first match with the team. In a match against Houston Dynamo he passed to Terry Dunfield, who scored, and at the end of the game said he was "delighted" with the result. Manager Paul Mariner named O'Dea team captain in September, succeeding the injured Torsten Frings. The following month, he was unable to play a match against Montreal Impact due to a thigh injury sustained during World Cup qualifying play for Ireland. In O'Dea's first season for Toronto, he played nine times as Toronto finished tenth in the Eastern Conference. O'Dea was employed at left back for the 2013 season after the regular player at that position was injured. According to him, it had been two years since he had previously played left back. O'Dea scored his first goal for Toronto on 3 July 2013 in a 3–3 home draw with Canadian rivals Montreal Impact. Because of his "keen sense of positioning and timing" against Sporting Kansas City, he was named to the Team of the Week for 12 March. Originally part of a transfer (a "win-win for both parties", according to head coach Ryan Nelsen, since O'Dea was the highest-paid player in the league), he was released by Toronto on 18 July 2013 to sign with FC Metalurh Donetsk. Club president Kevin Payne wished him luck and hoped he would return in the future. O'Dea played a total of 26 times for Toronto, scoring one goal and setting up three, and was succeeded as team captain by Steven Caldwell.

After a match against the Czech Republic, O'Dea said he dreamed of being named to the Irish squad for UEFA Euro 2012. Although he was on the roster for the tournament in Poland and Ukraine, he did not appear; the Irish were eliminated from the group stage. O'Dea scored his first senior goal for Ireland, an 88th-minute header, in a World Cup qualifying match against the Faroe Islands on 16 October 2012 which Ireland won 4–1.

After his release from Toronto O'Dea signed a three-year contract with Ukraine's FC Metalurh Donetsk. He debuted for the team in a 20 July, 2013 1–1 draw with FC Karpaty Lviv, playing 46 minutes before being substituted. O'Dea scored his first goal for Metalurh in his second game, a 2–1 away win over Vorskla Poltava. He left the club in August 2014, terminating his contract two years early due to the unrest in Ukraine. O'Dea described the situation in the country as "hostile and intense, but also surreal".

O'Dea then signed with championship club Blackpool in December 2014, making his debut in a 6–1 loss to Bournemouth. Bournemouth's fourth goal was scored by Brett Pitman, converting a penalty shot incurred by O'Dea (who fouled Callum Wilson in the penalty area). Against Wolverhampton Wanderers, the BBC reported that he "got into a terrible muddle trying to cut out a pass from Kevin McDonald" and allowed Benik Afobe (in his first game for Wolverhampton) to score the second goal. O'Dea was injured in a match against Nottingham Forest in February 2015, forcing him to miss the game with Blackburn Rovers. Released when his contract expired in May, he said the club had a "disastrous season". O'Dea played 20 times for Blackpool.

Although the Toronto Sun reported in May 2015 that O'Dea might re-sign with the city's MLS club, he signed a contract until 22 December with Indian Super League club Mumbai City FC, managed by Nicolas Anelka. Calling his signing "a new experience, a new chapter", he said he knew little about the quality of football in the league. O'Dea made his ISL debut on 10 October, starting in a goalless draw at Kerala Blasters. He left the club after making nine appearances.

O'Dea signed a short-term contract with Dundee in January 2016. On 22 March 2016, he signed a new three-year contract. In June 2017, O'Dea was named as permanent club captain by Dundee, having performed the role during the previous season in place of the injured James McPake.

On 7 May 2019, O’Dea announced in a long-form announcement on his Twitter account that he would be leaving Dundee at the end of the season, and that this would mark the conclusion of his last season as a full-time professional footballer.

O'Dea signed for his local side East Kilbride in May 2019 but left in August without making a single Lowland league appearance for the club. O'Dea left to focus on his coaching commitments with Motherwell full time.

O'Dea was appointed to a coaching position with Motherwell in May 2019. In September 2019 he left Motherwell and returned to Celtic to become manager of their under-18s.