Tim Deavin played for the Kookaburras, the Australian men's Hockey Team. He first played for the Australian senior national team in 2010. He won gold at the 2010 and 2011 Men's Hockey Champions Trophy, bronze at the 2012 London Olympics and gold at the 2014 World Cup.
Deavin made his national team debut in 2010. In 2010 and 2011, he won a gold medal at the Champions Trophys in Germany and New Zealand. He Played in the Sultan Azlan Shah Cup in Malaysia in 2010(3rd), 2011(1st) and 2013(1st) where he was named in the Azlan Shah Cup Eleven. In December 2011, he was named as one of twenty-eight players to be on the 2012 Summer Olympics Australian men's national training squad. In February 2012 he played in a four nations test series with the teams being the Kookaburras, Australia A Squad, the Netherlands and Argentina, where Australia won. He played in the London Olympics where the team won bronze. At the 2014 Hockey World Cup, Deavin and the Kookaburras won back to back golds in front of a packed crowd at Den Hague in the Netherlands.