Rogers Communications, Inc., the network's parent company, announced the move on Thursday.
Rogers Media president Rick Brace said the termination of Zaun's contract with the network is "effective immediately."
The 46-year-old enjoyed a 16-year Major League Baseball career, spending five seasons with the Blue Jays. The former catcher also played for the Baltimore Orioles, Florida Marlins, Texas Rangers, Houston Astros, Kansas City Royals, Colorado Rockies, Tampa Bay Rays and Milwaukee Brewers.
"This week, we received complaints from multiple female employees at Sportsnet regarding inappropriate behaviour and comments by Gregg Zaun in the workplace," Brace said in a statement. "After investigating the matter, we decided to terminate his contract, effective immediately."
"This type of behaviour completely contradicts our standards and our core values. We must all be held to the same standard - regardless of our position, our contributions or our status.
"We believe in a professional workplace where all employees feel comfortable and respected. We believe in a culture where our employees share their feedback openly and honestly."
"We are grateful to the employees who spoke with us and we will take every measure to protect their privacy."
Zaun joined the network in 2011. He is also a regular on Sportsnet radio shows.