Liam Justin Messam (born 25 March 1984) is a New Zealand rugby union player who plays in Super Rugby for the Chiefs, for whom he is the most-capped player in history, and for Waikato in the ITM Cup. Messam predominantly plays as a blindside flanker. After the retirement of then Chiefs captain Mils Muliaina, Messam was named the team's new co-captain from 2012 onwards, alongside Aaron Cruden.
In October 2008, Messam was selected in the All Blacks end of year tour squad to tour Hong Kong and Europe. He played one test against Scotland and one match against Munster. He subsequently appeared several more times for New Zealand but was dropped a month out of the 2011 Rugby World Cup in favour of Victor Vito. Since debuting in 2008 he has won 40 test caps.
In 2004, at the age of just 20, he captained the New Zealand sevens teams to its fifth IRB Sevens World Series title and in 2005 led the team to the final. Messam also played in the New Zealand sevens teams that won gold at the 2006 Commonwealth Games and 2010 Commonwealth Games. In 2004 he was also named New Zealand Sevens Player of the Year.
Of Māori descent, Messam affiliates to the Ngāi Tūhoe iwi. Messam has also stated through his Twitter account and Fresh TV interview that he also has Samoan and Scottish heritage. He has played for the New Zealand Maori, including during the 2006 Churchill Cup and the 2010 centenary series, where he captained the side. In 2012 and 2013 Messam was awarded the Tom French Cup as Māori Player of the Year.
On 31 January 2015, Messam fought on the undercard of close friend Sonny Bill Williams' boxing bout.
Messam was selected for the 2015 Rugby World Cup as part of the All Blacks' 31-man squad. After the history-making tournament was finished, Messam announced the will to compete in the Rugby Sevens for the 2016 Olympic Games.
Messam was later named in the All Black Sevens' squad for the Wellington Sevens alongside All Blacks teammate Sonny Bill Williams.
The most capped player for the franchise, with two title wins as captain, Messam is arguably the greatest player in Chiefs history.