The 31-year-old, currently the highest-scoring Englishman in the Premier League with 13 goals, has committed to the Saints until the summer of 2016 and he hopes to end his career at St Mary's.
Lambert has been a permanent fixture in the side since the appointment of Mauricio Pochettino as manager in place of Nigel Adkins.
"I'm over the moon to sign with Southampton for another three years," said Lambert, who joined from Bristol Rovers in August 2009 for £1m.
"I am enjoying myself massively at this club and the aim now is to stay on for another three years and help push the club on further than where it already is.
"There is a lot of ambition in this club for the next few years and that is one of the main reasons that I have signed the contract - and that is why I want to end my career here.
"The core of players who have been together for two or three years are going to be here for another three or four years and that is a really good feeling."
Pochettino added: "Rickie Lambert is a very special player for Southampton. To have scored over 100 goals is a remarkable achievement, and one which he has made possible thanks to hard work and dedication.
"In my time at the club I have been impressed by his mentality and commitment to improving himself in training - attributes that have allowed him to adapt to the Premier League so well.
"I am delighted that Rickie has committed himself to the club for a further three years, and have no doubts that he will continue to deliver for Southampton as we look to push on to the next level."