Worldwide, Onso (Onso 
) is a very rare epicene first name. More frequently, Onso is the last name as well as the forename.
La, Analiza, Antonio, Richard, Joy Ann, Junalie, Vincent, Bernardo, Karia Marie, Josepina, Alfonso, Trinidad, Virgilio, Filomena, Ian Cris, Mercedita, Rosalinda, Joenelie Mae, Daisy Jane, Victoriano, Wilhelmina, Ninia Dulce, Melanie, Julito, Joemar, Alf, Marl, Afif, Ralf, Rita, Erla, Susan, Aylen, Karen, Pablo, Ramel, Razel, Daisy, Jonas, Eddie, Hamad, Zauda, Bernie, Ronald, Dexter, Gloria, Ralph Angelo, and Yutthaphong