The 28-year-old, who first joined the Stamford Bridge club in 2014, enjoyed the summer of a lifetime after winning the European championship with the Lionesses.
Bright was at the forefront of England's success, having put on a defensive masterclass throughout this summer's tournament.
The defender started in all six games and was most notably awarded the Player of the Match prize for her quarter-final performance against Spain.
Should the Blues vice-captain remain at Stamford Bridge for the duration of her deal, it will take her time at the club to over a decade. Bright is already the longest serving player for Chelsea Women.
The player arrived in London from Doncaster Rovers Belles and has since won 13 major trophies.
Bright is a six-time champion of England, a four-time FA Cup winner, two-time Continental Cup winner and also has one Community Shield under her name.
What's more, the player was named twice in both PFA Team of the Year and the FIFPro Women's World XI.
The 28-year-old was excited to share the news with Blues fans commenting: "Chelsea, the fans, the club, the people. Thank you for all your support so far.
"You're my home and I can't wait to continue fighting for more trophies. Cheers to the future!"
Commenting on Bright's extension with the club, general manager Paul Green said: "We are absolutely delighted that Millie has signed a new contract.
"Millie remains our longest serving player and her time with us has been key to our success.
"The way that she leads on and off the pitch is second to none and we are proud of how far she has come and all her achievements, including her most recent win at the Euro's which was a very proud moment for the club."