New Zealander Evans first joined the MW Arden GP3 squad for the 2011 campaign. His maiden win came in round three at Barcelona, then he triumphed in last year's ultra-tightfight for the title.
Team boss Julian Rouse was delighted to hang on to Evans for his next move.
"We have a great relationship with him, and have seen him grow in the last two years in a championship that was created to bring great drivers into GP2," Rouse said.
"We tested Mitch at the Barcelona and Jerez tests at the end of last year and were encouraged by his performance, especially as he was in the top 10 with drivers who have several years' GP2 experience.
"Also with everyone at Arden knowing Mitch so well, I am sure we can develop him as a front-running GP2 driver very quickly and efficiently."
Evans, a protege of Red Bull Formula 1 driver Mark Webber, joins race winner Johnny Cecotto Jr in the Arden line-up.