Andrea emerged on to the international scene in 2005, winning the U23 World Championship in Gamagori, Japan. Her debut season on the elite World Cup circuit in 2006 saw her finish as the 9th ranked athlete in the world and pick up a bronze at the Melbourne Commonwealth Games, out sprinting compatriot Debbie Tanner to grab a medal. Her achievements saw her named as BG International Rookie of the Year.

2007 saw Hewitt confirm her place among the world’s elite when winning an ITU World Cup for the first time in Kitzbuhe,l Austria and consistently racing at the front of BG World Cup’s and major championships.

Glasgow was the second Commonwealth Games for Andrea, placing 4th. She competed at the 2006 Games in Melbourne, placing 3rd one year after competing in her first triathlon. Andrea has won the ITU World Triathlon Series three times and has also competed at two Olympic Games: Beijing in 2008 where she placed 8th and London in 2012 where she placed 6th.