|Full name||Wayne St John O'Sullivan|
|Date of birth||February 25, 1974|
|Place of birth||Akrotiri, Cyprus|
|Height||5 ft 8 in (1.73 m)|
|Playing position||Right midfield|
|2005–2007||Central Coast Mariners||37||(1)|
|2011||Lake Macquarie City||11||(0)|
|1995||Republic of Ireland U21||2||(0)|
|2008–2009||Wellington Phoenix (asst.)|
|2009–2012||Newcastle Jets FC W-League|
|2013–2015||Central Coast Mariners (asst.)|
|* Senior club appearances and goals counted for the domestic league only.
Wayne St John O'Sullivan (born February 25, 1974) is an Irish retired professional footballer. Since retiring as a player he has worked as a coach.
Born in Cyprus, O'Sullivan played youth football for Swindon Town before making his professional debut with the club. In 2001, he moved to Australia, where he played in the National Soccer League and A-League, as well as one season in Singapore.
O'Sullivan represented Republic of Ireland at youth level.
O'Sullivan was part of the regular first eleven for Plymouth Argyle. At the time Plymouth were placed low in the Nationwide Division 3 (now Football League Two), he along with Paul McGregor and Martin Phillips were considered the most consistent players at the time. But in the summer of 2000 he headed to Australia to continue his playing career.
Following the demise of the old National Soccer League competition and the creation of the Hyundai A-League, O'Sullivan signed with Central Coast Mariners in late 2004 to play in the newly-formed A-League. At the club, he was a favourite among fans for his tenacity and energy on the field. After an inconsistent 2006–07 season with The Mariners, during which he was often deployed as a right-back, instead of his preferred right-midfield position, the hard-working midfielder/defender was released.
Although there is some controversy surrounding Lawrie McKinna's decision to release O'Sullivan, it was believed by many in the Mariners camp that he was past his best and for the club to continue to grow in a developing league, his release was necessary.
O'Sullivan came on as a substitute for Republic of Ireland under-21 in a win over Latvia in 1996 UEFA European Under-21 Championship qualification on 10 October 1995. He made a total of two appearances for the side.
After being released by Central Coast Mariners, O'Sullivan had spent months trying to find a spot in another football team to continue his playing career, but was not successful.
On Friday, 18 May 2007, O'Sullivan was named Assistant Coach for A-League club Wellington Phoenix on a two-year deal. He worked alongside Ricki Herbert, Luciano Trani and former Celtic goalkeeper Jonathan Gould.
On Thursday, 21 November 2013, O'Sullivan was named Assistant Coach for the Central Coast Mariners on a contract until the end of the 2014–15 A-League season, working alongside newly appointed coach Phil Moss.