It will take the popular Jamaican into a 13th season at the Reebok Stadium and is confirmation of his well-being after a knee injury sidelined him for much of last season.
"I have been at Bolton almost my entire career and I wanted to stay here longer," he told www.bwfc.co.uk.
"I am looking forward to this pre-season because it is a fresh start."
The 32-year-old has made over 400 appearances for the Trotters and also featured four times for Preston in a loan move last season that many wondered would signal the end of his Bolton career.
Gardner was never convinced and always felt he could recover given the correct preparation.
"I hurt my knee after the season started last year and I had to play catch-up," he said.
"I had a bit of a break in the summer and went back to Jamaica for two weeks to give my muscles all the rest that I needed and spend time with my family.
"It was important that I prepared myself right because this is a big season for me and I want to make sure I enjoy it."
Source: PA
Source: PA