Born in New Zealand and schooled in Australia, Kate graduated from Hunter Valley Grammar School in 2002.
Gill made her debut for Australia in 2004 against New Zealand in Brisbane. As of July 2014 she has played 83 times and scored 40 goals for the Matildas.
In 2008, Gill played for the Newcastle Jets in the W-League, before moving to Sweden where she played with Sunnanå SK of Skellefteå in the Damallsvenskan league during 2009. In the upcoming winter, she moved to LdB Malmö for the 2010 season.