The 26-year-old actress will star in two episodes of the series' second season, reported Variety.
Currently, details of Hyland's character are being kept under wraps, but her role is being described as "special guest appearance".
Hyland's first episode date has also not been announced yet.
"Shadowhunters" is an adaptation of "The Mortal Instruments" books authored by Cassandra Clare.
The show stars Katherine McNamara, Dominic Sherwood, Alberto Rosende, Matthew Daddario and Emeraude Toubia, among others.