The pair reportedly got together in August, and Dobrev is close friends with Hough's sister, dancer/actress Julianne Hough. The couple was photographed hanging out at the Universal Studios' Hollywood Halloween Horror Nights event in Los Angeles on Oct. 5 but are no longer together.
Busy schedules contributed to the break up, a source told UsWeekly.
Dobrev previously dated her "Vampire Diaries" co-star Ian Somerhalder. They parted ways in May after three years together.
The actress made headlines earlier this month after she posted a topless photo on Instagram to help promote President Barack Obama's Affordable Care Act.