The 29-year-old, also the 2015 Most Valuable Player, beat off strong competition from Jonny Bairstow, Ashwell Prince and Matt Coles to claim the top award, which was voted for by his peers.
Rushworth had a sensational campaign with the ball, topping the LV= County Championship wicket charts with 83 scalps at an average of 20.61.
He said: “I am over the moon. It is a massive achievement. For myself this award is massive and the biggest individual award in county cricket.
“To be voted for by fellow players and your peers is a very privileged moment and one I’m very proud of. Hopefully it’s the next step to progressing towards further honours.
“The guys that have won it in recent years have gone on to play Test cricket, like Adam Lyth, Moeen Ali and Nick Compton, so that is definitely in my sights. Hopefully I have another good season next year and I can put my name in the hat for Test selection.”
PCA Team of the Year: Alastair Cook (captain, Essex & England), Alex Hales (Nottinghamshire & England), Joe Root (Yorkshire & England), Sam Northeast (Kent), Luke Wright (Sussex), Ben Stokes (Durham & England), Alex Davies (Lancashire), Stuart Broad (Nottinghamshire & England), Matt Coles (Kent), Jeetan Patel (Warwickshire), Chris Rushworth (Durham).