The couple, who were together for five years, ended their engagement earlier this month, TMZ reports.

According to People, who confirmed the news, the Bad Romance singer and the Vampire Diaries actor decided to end things as "work kept them apart a lot".

"Chicago Fire keeps him in Chicago and her work is almost always elsewhere," an industry source told People.

Gaga, 30, met Kinney, 35, after he was hired as an actor for the music video for her song You and I in 2011.

The pair played lovers in the music video, in which Gaga wore her mother's wedding dress.

After four years of dating, Kinney proposed on Valentine's Day 2015.

"He gave me his heart on Valentine's Day and I said YES!" Gaga shared on Instagram at the time.

In a 2014 interview with Howard Stern, Gaga said she could see a future with Kinney.

"He is the right guy," she said. "How do we know? It's this feeling ..."

Following this year's Oscars ceremony - at which Gaga gave a chilling performance of her song 'Til It Happens to You from campus sexual assault documentary The Hunting Ground - Gaga shared a picture of the couple kissing backstage.

"I never thought anyone would ever love me because I felt like my body was ruined by my abuser. But he loves the survivor in me. He's stood by me all night proudly and unashamedly. THAT'S a real man," Gaga captioned the picture.

Lady Gaga is currently on holiday with friends in Mexico. Neither party's representation have commented on the split.