Originally a goal-kicking fullback, Cleary was a Manly-Warringah Sea Eagles junior before moving to play Reserve Grade with the Sea Eagles in 1992 and 1993. He started his first grade career with the Sea Eagles in 1992 playing two games before getting his chance after the team's first choice fullback Matthew Ridge suffered a season-ending injury in mid-1993. Cleary filled the fullback spot and also proved himself an accurate goal-kicker, filling in for Ridge on both counts and helping Manly to 4th place and a finals berth where they were bundled out 4-16 by the Brisbane Broncos in the Qualifying Final. In his 15 first grade games for Manly, Cleary scored 8 tries and kicked 50 goals for a total of 132 points.
With Ridge set to return in 1994 Cleary signed with Manly's local rivals the North Sydney Bears for 1994 and 1995 seasons where he mainly played in the centres due to the emergence of fullback Matt Seers. He also was the team's 2nd choice goal kicker behind Jason Taylor and in 37 games for the Bears he scored 15 tries but kicked only 5 goals for a total of 70 points.
Cleary began playing for the Sydney City Roosters from seasons 1996 through to the 1999 season making 81 appearances for the tri-colours. In 1998, Cleary was The NRL top point scorer with 284 points.
New Zealand Warriors
Cleary signed with the New Zealand Warriors for the 2000 season before the fullback retired at the end of the 2002 season following the warriors grand final loss.
Coaching career
After leaving the Warriors Cleary originally intended to join the Huddersfield Giants in the Super League but instead retired to take up an opportunity to join the Sydney Roosters as the NSWRL Premier League coach. In 2004 he coached the team to the Premiership.
New Zealand Warriors
Cleary coached New Zealand to the 2011 NRL grand final against Manly; they lost 24–10. In the following weeks, Cleary announced he was leaving to join Penrith.
Penrith Panthers
Early season injuries and some poor form from the Penrith Panthers saw a tough start to Cleary's return to Sydney with Penrith sitting 15th after Round 19 of the 2012 NRL season with a 4-13 record. In 2014, Cleary took Penrith to the preliminary final before losing to Canterbury. He was also named Dally M coach of the year in the same season. He was fired on 19 October 2015 after avoiding the wooden spoon with a final round victory over Newcastle.
Wests Tigers
He was appointed as the coach of the Wests Tigers on 3 April 2017. In Round 22 of the 2017 NRL Season, Cleary coached the Wests Tigers and coached against his son, Nathan Cleary who was playing for the Penrith Panthers in a losing effort by 28–14. In the 2018 season, Cleary guided Wests to a ninth-placed finish narrowly missing out on a finals spot. On 28 October 2018, the Wests Tigers released Cleary from the final two years of his contract. Cleary also sent a departing text message to the tigers playing group saying "G'day boys I hope this finds you well and enjoying your time off, I was writing to you in the hope of beating the press.. to let you know that I will no longer be your coach at Wests Tigers. "This is an extremely uncomfortable situation for me as I have genuine fondness for the club, and I have loved coaching you all.. I understand that this situation has caused some pain for people that I care about, along with putting the club in an awkward situation... I do not feel good about this. "I would have preferred to do this in person but time and circumstances have made that impossible. I hope we meet again soon and I wish you all the very best in the future. You have my number and I am always open for a chat if you wish. Iv."
Penrith Panthers (2)
On 29 October 2018, the Penrith Panthers confirmed the return of Ivan Cleary as head coach, on a 5-year deal, beginning in 2019. Ivan linked with his son Nathan Cleary and began his second stint as head coach at the Penrith Panthers. Cleary's second spell in charge at Penrith got off to a bad start with the club winning only 2 of their first 10 matches leaving the team bottom of the table. Penrith would then go on to win their next 7 games in a row leaving them just outside the finals places. In a must win game against the Sydney Roosters in round 24, Penrith lost the match 22-6 at the Sydney Cricket Ground which meant that the club would miss out on the finals series for the first time since 2015. In round 8 of the 2020 NRL season, Cleary coached Penrith to a 19-12 victory over the Wests Tigers. Following the full time siren, angry Wests fans shouted abuse at Cleary who was inside the coaches box. Cleary proceeded to wave and blow kisses at the Wests Tigers supporters.
