The new deal will keep the 26-year-old at the KC Stadium until 2012.
Manager Phil Brown told the club’s official website: “Over the last two or three years, I have seen that Boaz Myhill is a Premier League goalkeeper, there is no doubt about that.
“He stepped up to the plate very admirably last season, albeit in difficult circumstances with Matt Duke breathing down his neck all year.
“I know Dukey got himself into the first team for six or seven games and that must have surprised Bo at the time, but he has come back stronger.
“I’m delighted to get Bo tied up to a decent contract long term.”