The 30-year old Finnish international had been in talks with the Trotters for some time regarding a contract extension and will now pen the new deal when he returns from his summer holidays.
Jaaskelainen's agent Peter Harrison confirmed that his client was delighted to be prolonging his stay at the club who he has been with since signing from VPS Vaasa in November 1997.
"I can confirm Jussi has agreed a three-year deal, it has all been agreed," Harrison told Sky Sports
"Jussi is delighted it has all been sorted out and he will be signing when he returns from holiday. He is really looking forward to next season when Bolton will make their European debut."