After six years and 137 games as skipper Boak will step aside to allow someone else to take over.
The 30-year-old told Port Adelaide's website it was the right time to make a chance.
"Six years into the job I think it’s the right time to hand it over to the next person, whoever that is,” Boak said.
“I’ve hit 30 now and I’m at the back end of my career so I think it’s a good chance for a change of direction.
“The club is in a good position with everything that’s been set up off the field and on the field with all the players we’ve got in in the past few years, so it’s a perfect opportunity for the next person to come in and take the lead and push the group forward.
“I got drafted to this great club when I was 18 and my dream was just to play one game for the Port Adelaide Football Club.
“So, when I was told I was going to captain it was one of the best days of my footy career and every time I put on that number one it was a great honour.
“It’s something I hold close to me and something I’ll look back on after my career and feel so very proud of.”