The Scotland international midfielder said he was delighted to extend his stay after what he described as a landmark campaign for the club.
"It feels brilliant and I'm absolutely delighted," Christie said. "Especially after the way the season finished, it's been such an incredible year for the club having qualified for Europe. I'm looking forward to next season already.
"With the World Cup coming up, it felt like the perfect time to sign before heading away for that, and now I can fully focus on the future.
"When I joined the club, I had aspirations to play in the Premier League and I strongly believed we could get promoted, but the journey we've been on since then has been incredible. Since getting promoted, we've never really looked back."
Christie added that reaching Europe with Bournemouth made the moment even more special. "Five years on, to now be in this position signing a new contract, it's really special."
Internationally, Christie has also been named in Scotland's squad for the 2026 FIFA World Cup, with head coach Steve Clarke confirming him in the final 26-man group.
2026 FIFA World Cup will mark Scotland's return to the men's finals for the first time since 1998. They have been drawn in Group C, where they will face Haiti, Morocco, and Brazil.
Scotland open their campaign against Haiti in Boston (Foxborough, Massachusetts) on Sunday, as Christie prepares for a major summer both internationally and at club level.
FIFA have defended the official attendance figure from the 2026 FIFA World Cup Group A clash between South Korea and Czech Republic after visible empty seats inside the stadium sparked questions over crowd numbers.
Carlo Ancelotti has confirmed that Neymar will miss Brazil's 2026 FIFA World Cup opener against Morocco on Sunday, as the forward continues his recovery from injury.
Minister of Sports, Arts and Culture, Gayton McKenzie, has publicly backed Bafana Bafana midfielder Sphephelo Sithole after the midfielder endured a difficult outing in South Africa's opening match of the 2026 FIFA World Cup against Mexico.
Jarell Quansah has attributed his place in England's 26-man World Cup squad to the difficult decision to part ways with Liverpool to join Bayer 04 Leverkusen last year.
