Clark is the son of Anglo-Indian parents; his father Bruce Clark is from Chennai and his mother Mary (née Boosey) is from Bangalore. He is the first male cricketer of Indian ancestry to represent Australia.

Clark finished a Master of Commerce, majoring in finance, in 2009 and then completed a degree in law at the University of Sydney. He worked as a real estate agent for 5 years before he pursued cricket.

Clark is married to Michelle, with whom he has two children, Lachlan and Sophie.

New South Wales

Clark started out playing first-grade cricket for Sutherland District Cricket Club, opening the bowling with Glenn McGrath in that club's Sydney Grade Cricket grand final win in the 1995-96 season. Clark made his first-class debut with the New South Wales Blues on 4 February 1998 against Tasmania at the Sydney Cricket Ground. He had a poor debut season, taking only 4 wickets at an average of 76.75. The 1998–99 season also saw Clark struggle as he took only 2 wickets at an average of 220.50. After his first 7 first-class matches, Clark averaged 124.66 with the ball. His poor performances led to him being dropped during the 1998–99 season and he did not play a first-class match for over 2 years.

Clark returned for New South Wales in the 2000–01 season and enjoyed a solid comeback season, taking 8 wickets at 25.75 in the 3 matches he played. After these performances, he retained his place in the side for 2001–02, a season which would prove to be his breakthrough one. Clark played 9 matches in the season, taking 45 wickets at an average of 23.26. He claimed four 5 wicket hauls and finished second behind Australian paceman Michael Kasprowicz in the leading wicket-takers list. With a promotion to a national contract, Clark had another strong season for New South Wales in 2002–03 securing 30 wickets at an average of 30.33. While the 2003–04 season was less successful for Clark, taking 23 wickets at 38.26, 2004–05 saw a return to form as he took 40 wickets at 24.77.^[7] Clark only played 4 matches for New South Wales in the 2005–06 season yet still managed to take 17 wickets at 22.05.^[13]

Clark's full-time call up to the national team in 2006–07 also saw him play fewer matches in the 2006–07 domestic season, yet the three matches he played saw him take 21 wickets at 14.47.^[14] During this season, Clark recorded his highest ever first-class score with 62 off 43 balls against South Australia at the Adelaide Oval. Clark bought up his half-century off 34 balls and his innings included 4 sixes and 3 fours. In the same match, Clark claimed his best ever first-class figures at the time, taking 6/39 in South Australia's second innings.^[15] In the next match he played for New South Wales, Clark exceeded these figures by taking 8/58 against Western Australia at the WACA Ground. Clark ended up taking 10 wicke