Baines put pen to paper on a new four-year deal with the Toffees earlier today, ending speculation linking him with a move away from the club in January, with Manchester United said to have been interested.
The England international, who will be 33 when his new deal expires, insists that he "couldn't be happier" after committing his future to the Merseyside outfit.
"I am delighted to have agreed the new deal. I am very happy at Everton and always have been. It's a fantastic football club and I am excited about what we can achieve here in the next few years," Baines told the club's official website.
"I've loved every minute of being here since I first joined in 2007 and I couldn't be happier."
Martinez has also expressed his joy at tying the left-back down to a new deal, describing it as an "important moment" for the club.