Milligan is studying at Melbourne's Film & Television Studio International. In 2008, Milligan began his acting career in the soap opera Neighbours, playing the character of Kyle Canning. In January 2011, it was announced that Milligan would be promoted to regular cast member. In 2009, he played a cameo role as a student on the Australian police drama Rush. In late 2009, Milligan filmed thirteen episodes on the television series Dead Gorgeous in which he played main character, David. He played a part in the HBO miniseries The Pacific for all ten episodes.
