The Power vice-captain attracted interest from a host of clubs in his home state, including Geelong, North Melbourne and Carlton, but has opted to stay at Alberton Oval.
The 24-year-old has reportedly put pen to paper on a $650,000-a-year deal, making him Port's highest paid player.
"I'm so relieved to have got the deal done after what has at times been a challenging year for me personally and for the club," Boak told Port Adelaide's website.
Boak delayed contract negotiations during the season in a bid to weigh up his options amid speculation he was eager to return home to be closer to his mother and two sisters.
"The big decision I had to make was whether to return home to be closer to my family or stay at the club I love," he said.
"I've been in regular contact with my mum and sisters about my future and they've been unbelievably supportive with the decision that I've made."
Following the re-signing of emerging quartet Jasper Pittard, Jarred Redden, Aaron Young and Cameron O'Shea just days ago, Boak said he was excited about the prospect of continuing at Port Adelaide and thanked its members and fans for their support.
"The last two years doesn't reflect the talent of our group and I think we're going to realise our potential in the near future," he said.
"I'm very excited about what lies ahead and that was another major factor in my decision to stay.
"I've had a huge amount of support from a lot of different people this year.
"Our supporters have just been fantastic. I've been getting a lot of well wishes through Twitter, Facebook and even letters being sent into the club which has been quite overwhelming.
"And the support I've had from the coaches, my team mates and staff has been terrific.
"At no stage did they put pressure on but allowed me time and space which really helped in my decision process."
Port Adelaide general manager Peter Rohde was rapt with the coup but said he never doubted Boak's commitment to the club despite Matthew Primus' sacking as coach delaying negotiations.
"Travis is obviously a key player for our club who has an amazing work rate, wins a lot of the ball both inside and out and generates a lot of inside 50s for our forwards," Rohde said.
"He is an important part of our leadership group, is extremely popular around the club and drives the standards for our entire playing group through the way he trains and prepares.
"We got a clear indication several weeks ago that Travis wanted to stay and we had been working through some details since that point.
"After the departure of Matthew Primus as senior coach Travis naturally wanted to get some clarity on where the club was heading."Since debuting in 2007, Boak has played 108 games after being taken at pick five in the 2006 national draft and has been earmarked as a future Port captain.