The 29-year-old right-hand batsman has switched from the Hobart Hurricanes, where he has played 45 T20 games in the past six years.
Wells played six Big Bash games for the Hurricanes last season, scoring 137 runs in five innings at a rate of 130.47. His best knock of 55 from 37 balls was made against the Adelaide Strikers at Adelaide Oval in January.
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Strikers coach Jason Gillespie said: “We think that Jon can absolutely flourish in Adelaide and we’re delighted to secure his services.
“We’ve had some experienced players move on, but to secure a guy who’s played a bit of T20 cricket is very good for us.”
Wells, originally from Tasmania, scored two Sheffield Shield centuries for Western Australia last season.
“I am really excited to be joining a talented and youthful squad,” he said.
“The Adelaide Oval is one of the best in the world and the atmosphere the fans bring is amazing.
“I’m really looking forward to working with the lads and the coaching staff to bring success to the Strikers.”
Strikers BBL|07 Squad
Ben Laughlin, Alex Carey, Wes Agar, Jono Dean, Jake Lehmann, Michael Neser, Billy Stanlake, Jake Weatherald, Colin Ingram, Jon Wells