The European champions kept a pair of veterans in the fold on Friday.
Chelsea confirmed that France striker Olivier Giroud and Brazil defender Thiago Silva had signed new deals as the pair's respective contracts were set to expire at month's end.
"Olivier has been such a crucial part of so many big moments for this club, from his contribution to our FA Cup victory in 2018 to scoring 11 goals on the way to winning the Europa League in 2019," Chelsea sporting director Maria Granovskaia said in a statement. "He has continued to score significant goals, and we will never forget his effort against Atletico Madrid on the way to winning the Champions League this season.
'With so much to still to play for, there was only one decision we could make when we exercised the option to extend his contract back in April.’
The 34-year-old Giroud joined the Blues in a January 2018 move from London rivals Arsenal. With Chelsea, Giroud has won an FA Cup title, the 2019 Europa League title and last week's Champions League.
In 119 appearances across all competitions over four seasons, Giroud has 39 goals for Chelsea.
A World Cup winner, Giroud has been capped 107 times by Les Bleus and is a member of the France squad at this month's Euro.
Silva, 36, just completed his first season at Stamford Bridge since arriving on a free transfer from Paris Saint-Germain.
"When we brought Thiago Silva in last summer, we knew we were adding a world-class player to the squad," Granovskaia said. "Thiago has duly shown everyone at Chelsea his immense quality throughout this season, and he has had a huge influence on and off the pitch for us. We said when he signed that we hoped Thiago would add new trophies to his impressive list of honours, and he has done just that with our success in the Champions League this weekend. We now hope that he carries on in exactly the same fashion in the coming year."
In 34 appearances for the Blues across all competitions, Silva scored twice.
Internationally, Silva has been capped 93 times by Brazil, with whom he won the 2019 Copa America.
The moves come on the same day the Blues announced a new two-year deal for manager Thomas Tuchel.