The Ultimate Fighting Championship (UFC) veteran has put pen to paper on an exclusive five-fight contract, committing his immediate future to the organisation.
Mills (15-5, 2 NC) has spent the last two years of his career with the UFC, where he clocked up a 2-1-0-1 record.
The 30-year-old Gloucester native made a winning start to his UFC career in November 2011, picking up a KO of the Night bonus after taking just 40 seconds to dispose of Chris Cope.
In his only official UFC defeat, Mills suffered a second-round TKO loss to fourth-ranked welterweight Rory McDonald last April but rebounded with a win over Duane Ludwig in Nottingham in September.
At UFC on Fuel TV 7 at London's Wembley Arena last month, Mills was beaten by Matt Riddle by split decision, but the result was later overturned as a ‘no contest' after Riddle failed a drug test.
"Che Mills is the best UK welterweight outside of the UFC at the moment so I'm extremely happy that he has decided to come on board," said Cage Warriors CEO Graham Boylan.
"A fighter of his calibre wouldn't have been short of offers but the fact that Che has opted to sign for Cage Warriors is proof that the guy is determined to return to the top. I have no doubt that he'll get there too.
"I'm a big fan of Che Mills. When the UFC recently released a bunch of guys, Che was the one I really wanted to bring in. He comes from a great camp and is always exciting to watch.
"As is the case with all fighters, I believe Cage Warriors is the perfect platform to help Che to achieve his goals and show the world that they still haven't seen the best of him."
A contestant on season nine of The Ultimate Fighter, Mills previously fought for CWFC in October 2010, when he scored a unanimous decision win over fellow UFC veteran Jake Hecht at Cage Warriors 38. He also holds two notable wins over Bellator star Marius Zaromskis.
Che Mills will make his return to Cage Warriors action in the coming months. Details of his next bout will be released shortly.