Rockwell, who recently won a Golden Globe for his performance in the film "Three Billboards Outside Ebbing, Missouri," will host "SNL" on January 13, reported Variety.
Halsey will join Rockwell, who is also marking her debut as musical guest.
Chastain will host the "SNL" on January 20. Troye Sivan will appear as musical guest for the first time.
"SNL" veteran Will Ferrell, who was a cast member from 1995-2002, will return to the show's stage as host for the fourth time on January 27.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)