Changes to provincial regulations rescinded long-standing rules against winery openings on certain dates.
Two of those dates were Good Friday and Easter Sunday.
Officials say people should check winery websites to confirm hours of operation.
"As an industry that relies heavily on tourism, this is an important milestone for Ontario's designated wine regions," said Allan Schmidt, chair of the Wine Council of Ontario. "And while not all wineries will choose to remain open, we expect many to do so."
Bonny Quick lives near a winery in Essex County, southeast of Windsor, Ont.
She says the winery staying open near her house on Good Friday could come in handy.
"People travel on those days and visit family. It would give our wineries more exposure when you can come in on holidays," she said. "With out of town company, maybe nothing in the house, I could run over to the local wineries and pick up something from them."
At Cooper's Hawk Vineyards in Harrow, Ont., staff say even adding one extra day over Easter Weekend could help clients.
"I've been [here] working and doing things on a Good Friday before, in previous years, and seen people come in and I've had to hide because we're closed," said winemaker Rori McCaw.
The new rules could help in marketing new wines at Cooper's Hawk.
"We usually do our new whites and have them release Easter Weekend but usually we're not open," McCaw said. "So it's a nice weekend to get local people, plus others who are visiting, to come in and see our new whites."