From the experts:
This concise one-syllable name, Hebrew for heart or the Russian form of Leo, has definite potential, being more unusual than the increasingly popular Levi.
The leonine Lev is the Russian birth name of the great novelist Tolstoy, and the mother of Liev Schreiber has stated that she named him in honor of the writer. In the Chaim Potok novel My Name is Asher Lev, about a Hasidic Jewish boy in New York, Lev is the character's surname.
Actress Candace Cameron has a son she named Lev.