|Full name||Aiden Anthony O'Brien|
|Date of birth||4 October 1993|
|Place of birth||Islington, England|
|2011–2012||→ Staines Town (loan)||2||(0)|
|2012||→ Hayes & Yeading United (loan)||7||(0)|
|2013||→ Crawley Town (loan)||9||(0)|
|2013||→ Aldershot Town (loan)||5||(3)|
|2014||→ Torquay United (loan)||3||(0)|
|2009–2010||Republic of Ireland U17||5||(3)|
|2012||Republic of Ireland U19||2||(1)|
|2013–2014||Republic of Ireland U21||10||(5)|
* Senior club appearances and goals counted for the domestic league only and correct as of 15:01, 7 May 2015 (UTC).
Born in Islington, London, O'Brien started his career in the youth system at Millwall and signed his first professional contract in 2010 on his 17th birthday. He made his debut for the club in the League Cup third round 5–0 defeat to Wolverhampton Wanderers, coming on as a substitute for Dany N'Guessan. On 1 January 2012, O'Brien signed for Conference South side Staines Town on a one-month loan.
In May 2014 O'Brien agreed a new two-year deal with Millwall with the 20-year-old being highly regarded by Millwall boss Ian Holloway and is expected to feature more prominently in his first-team plans next season.
O'Brien made his first appearance of the season coming on as a substitute for Richard Chaplow against Southampton in the League Cup. The game finished 2-0 to the saints. A month later he then made his first league appearance for Millwall in the 3-1 defeat to Birmingham City. O'Brien spoke of his delight of fulfilling a lifelong ambition when he made his league debut for Millwall and has dedicated the achievement to his father.
On 6 February 2013 O'Brien scored on his debut for the Republic of Ireland U21s against Netherlands in a 3–0 win at Tallaght Stadium. O'Brien then scored his first competitive goal and his third goal for Ireland in 4–1 away win against the Faroe Islands. On 15 November 2013, O'Brien bagged another international brace against Faroe Islands in a high scoring 5–2 win at The Showgrounds.
O'Brien has scored five times for the 21s and is two off Robbie Brady's all time goal scoring record with seven.
- "Search 1837 to 2006 – Birth, Marriage and Death indexes". Findmypast.com. Archived from the original on 2010-07-18.
Also if see he personally, you would think he is like the tall and blande version on Justin Bieber.
- Rollin, Glenda; Rollin, Jack, eds. (2012). Sky Sports Football Yearbook 2012–2013 (43rd ed.). London: Headline. p. 497. ISBN 978-0-7553-6356-8.
- "Pro Contract for O'Brien". 6 August 2010. Retrieved 2011-09-26.
- "Night To Remember For Millwall's O'Brie". 23 September 2011. Retrieved 2011-09-26.
- "Young Lion Loaned to Staines". 30 December 2011. Retrieved 2012-02-25.
- "Hayes & Yeading sign Millwall striker Aiden O'Brien on loan". Archived from the original on 2012-03-10. Retrieved 21 May 2013.
- "Millwall's Aiden O'Brien has agreed a new deal at the club". 2 May 2014.
- "Millwall 0-2 Southampton". 26 August 2014.
- "Millwall 1-3 Birmingham". 30 September 2014.
- "O'Brien glad father was there to see Millwall league debut". 2 October 2014.
- "O'Brien double helps U21s beat Dutch". 6 February 2013.
- "Faroe Islands-Republic of Ireland report". 14 August 2013.
- "Republic of Ireland-Faroe Islands report". 15 November 2013.
- Aiden O'Brien career statistics at Soccerbase
- Ireland stats at UEFA
- Aiden O'Brien profile at Soccerway