The Pilgrims have paid the Gulls an initial fee of £15,000 for the target man, the first player Argyle have paid a fee for since the summer of 2012.
The 26-year-old has scored four goals for Torquay this season and scored eight times in 17 games last season as he helped the Gulls avoid relegation.
Blissett joined National League Torquay in January 2016, and signed a new deal at Plainmoor in the summer.
League Two Argyle have not disclosed the length of the former Bristol Rovers striker's contract.
He is the second player to move to Home Park since the transfer window opened, with Czech defender Jakub Sokolik joining on Wednesday after being released by Southend United.
Find all the latest football transfers on our dedicated page.
Plymouth Argyle have signed Torquay United striker Nathan Blissett.