The 44-year-old actress and 39-year-old actor marked the occasion by dedicating sweet posts to each other on Instagram.
"Happy First Anniversary love of my life nothing compares to you. te amo. #thebreakerspalmbeach. I will never forget that face," Vergara captioned a photo of Manganiello standing at the altar.
"Happy first anniversary to the love of my life!" the actor added in Spanish to a picture of their first dance.
Vergara and Manganiello tied the knot at The Breakers resort in Palm Beach, Fla., in 2015 after more than a year of dating. The actress, who shares 24-year-old son Manolo with her ex-husband, said in February that she'd be open to having children with Manganiello.
"I became a mother very young -- at 20 -- so I feel like I've been a mother my whole life," she told Net-a-Porter magazine. "Now that I'm 43 and my son is 23, it's funny to see some of my girlfriends raising young kids."
"I wouldn't mind another child: my husband is younger than me and he wants kids so we're trying to figure out what we're going to do," the star revealed. "The idea of doing it all again doesn't scare me but, hey, it's not like it's going to happen naturally, is it?"
Vergara is open to in-vitro fertilization, having previously frozen embryos with ex-fiancé Nick Loeb. She is best known for playing Gloria Delgado-Pritchett on the ABC sitcom Modern Family, which airs Wednesdays at 9 p.m. ET.