After joining the Wanderers in June 2014, Hamill made an immediate impact in the club's AFC Champions League success and played in both legs of the two-legged final.
The 22 year-old played 15 A-League games, represented Western Sydney in Asia and the FIFA Club World Cup before his campaign was curtailed by a thigh injury.
"I'm excited and grateful for the opportunity the club has given me and I can't wait to work hard and bring back the success that the club had in its first two and a half years," Hamill said.
"I love being here. My mum, dad, auntie and uncle have been members since before I joined the club and it’s part of what makes the Wanderers so special.
"We're a family club, we're a community club and we’re a winning club. It makes a combination you can’t say no to."
Wanderers CEO John Tsatsimas was thrilled to confirm Hamill's re-signing.
"Brendan is the type of player that we want love seeing at our club," he said.
"He’s talented, he’s a local boy, he has a terrific attitude and he is passionate about the community. Brendan fits into Western Sydney Wanderers in regards to both our club values and playing style."
The Wanderers face Guangzhou Evergrande in China on Tuesday night needing a win tohave any chance of progressing from Group H.
