Dobrev was born in Sofia, Bulgaria and moved to Canada at the age of two, where she was raised in Toronto, Ontario. She speaks fluent French, English, and Bulgarian. Her mother is an artist, and her father is a computer scientist. She has one older brother. She attended J. B. Tyrrell Sr. Public School and Wexford Collegiate School for the Arts in Scarborough, Ontario. From a very young age, she showed great enthusiasm and talent for the arts—dance, gymnastics, theater, music, visual arts, and acting. Dobrev attended the Dean Armstrong Acting school where she was discovered by many different talent agencies in Toronto.