Running a photo of her on the series' New York City set, The Hollywood Reporter said Monday that the actress, who will not be playing herself, is reuniting with "Hairspray" producers Neil Meron and Craig Zadan, two of the executive producers for "Smash."
Blonsky had earned a Golden Globe nomination for her portrayal of Tracy Turnblad in their hit movie adaptation of the stage musical.
"I can confirm that she is recurring on 'Smash,' but I can't provide any further details at this time," an NBC spokeswoman for the show told Newsday. Blonsky's representatives did not respond to requests for comment.
The actress, 23, joins the recently hired Jesse L. Martin (Broadway's "Rent"; NBC's "Law & Order") on the show, which stars Katharine McPhee and Megan Hilty as actresses in a musical based on the life of Marilyn Monroe. Debra Messing, Jack Davenport and Anjelica Huston also star.
In December, Blonsky had joined the staff of Superstar Hairstylists, of Middle Neck Road in Great Neck, as a cosmetologist.
She tweeted at the time, "Its true Im workin @ Superstar Salon as a makeup artist & more Im proud 2 b workin & helpin pay bills BUT ill NEVER loose sight of my dreams. Just cause Im part time workin doesnt mean Im gonna give up on my dreams n dont give up on urs I might book something big soon keep positive."