The Scotland youth international was named on the substitutes bench for Bournemouth in their English Premier League clashes against Everton and Newcastle United earlier this year.
He has grown as a player since his call-up to the Scotland senior squad over the summer, and the club clearly felt it was time to lock him down for the foreseeable future.
Speaking on his new deal, McKenna revealed that he is excited for what the future may hold as he continues to develop.
“I’m delighted to sign a new deal with the club, who have been brilliant for me since I arrived. I feel like I’m improving every day working with the coaches and goalkeepers here.
“Being able to learn off experienced shot-stoppers like Đorđe Petrovic has really helped my game, and I’m looking forward to seeing what I can achieve in the coming years here as I further my development.”
AFC Bournemouth’s President of Football Operations, Tiago Pinto, also spoke on the new deal and says he looks forward for what is to come from the youngster.
“We’re pleased to see Callan commit his future to the club, as we believe he has good potential.
"He is someone that will continue to work hard and push for opportunities in order to keep improving his game, and we look forward to helping him develop further."