Daley, who was taken by the Stars out of the Ontario Hockey League in the 2002 draft, broke into the NHL the following season and has gone on to post 28 goals and 86 assists in 453 regular-season games with Dallas.
The 27-year-old Toronto native will receive $3.5 million for the first four years, $3.1 million in the fifth and $2.7 million in the final year of the deal.
"Trevor is a big part of our team and an important member of our blue line," Stars General Manager Joe Nieuwendyk said. "We expect him to continue to develop and grow as he takes an even bigger role on our team. We are pleased to have him under contract for another six seasons."
Daley is coming off a 3-year contract worth $6.9 million.