The four-time All-Star checked in with 2,530,713 votes, outdistancing Chicago's Willson Contreras (1,216,513 votes), St. Louis' Yadier Molina (1,068,485), Los Angeles' Yasmani Grandal (749,923) and Washington's Matt Wieters (680,644).
Posey's .340 batting average entering Monday eclipsed the .336 figure he posted when he won the NL batting title in 2012. He also owns a .421 on-base percentage. Both figures ranked third in the Major Leagues.
"It's no surprise to me what he's doing. He's always thinking of ways to get better," Giants hitting coach Hensley Meulens said.
Posey has thrived by taking control of his plate appearances.