Wells, 23, impressed in the T20 Blast last season, scoring 373 runs at 28.69 - with a strike rate of 138.66.
Wells said: "It's clear that the club is going in the right direction and it's really exciting.
"The environment created by the coaches is of elite performance and it's making the lads want to be a part of it."
All-rounder Tom Wells has signed a new two-year contract which will keep him at Leicestershire until the end of the 2018 season.