While there is no official term for someone who plays this instrument, these are the most commonly used names.
Dr. Dan Band
This ukulele player is more like a guitar god – East Bay Times
Guitalele - Wikipedia
GOT A UKULELE - Ukulele reviews and beginners tips: Ukulele accompaniment
Ukulele Karate for Your Classroom, Hi-YAHH! - West Music
Slack Key Ohana
Meet Del Rey, One of the Ukulele's Most Important Players and Teachers
Canberra Olympic star Luca Florez balancing music gigs and Capital Football games, The Canberra Times
Jimmie Rodgers' Hawaiian Music Advocacy
Brittni Paiva
15 Best Ukulele Players of All Time