The 42-year-old actress took to Instagram to mark their anniversary by sharing a photo of the couple, reported Ace Showbiz.
In the photo, Vergara donned a yellow printed dress while Manganiello sported a printed black shirt.
The "Hot Pursuit" actress wrapped her hands on her beau shoulder, while the "Magic Mike XXL" actor wrapped his hands on her waist.
"Happy 1st Anniversary love of my life!!! Never been so happy!!#lucky @joemanganiello," she wrote along with heart emojis.
Just last week, Vergara revealed that her wedding to Manganiello would happen soon.