Among the series ensemble cast are Jeremy Strong as Kendall, Kieran Culkin as Roman, and Sarah Snook as Siobhan, Logan's children employed by the company. Matthew Macfadyen stars as Tom Wambsgans, Siobhan's husband and Waystar executive; Nicholas Braun as Greg Hirsch, Logan's grandnephew also employed by the company; Alan Ruck as Connor, Logan's eldest child; and Hiam Abbass as Marcia Roy, Logan's wife. The series also features Peter Friedman, Natalie Gold, and Rob Yang, with Dagmara Domińczyk, Arian Moayed, and J. Smith-Cameron in recurring roles, before they were promoted to the main cast.