Overton was claimed off waivers by the Pirates on Monday, Jamie Campbell of Sportsnet reports.
Overton was designated for assignment by the Blue Jays on Friday, but he'll land a spot on Pittsburgh's 40-man roster after he tossed 6.2 scoreless innings across four appearances in the big leagues this year. The right-hander has spent most of the season with the Triple-A club and has been optioned to Triple-A Indianapolis, Alex Stumpf of DKPittsburghSports.com reports.