One of Sloyan's earliest feature film credits was the 1973 classic The Sting. He later had a role in the 1978 mini-series Centennial. His voice is familiar to many as he is the spokesperson for Lexus.
Sloyan made several appearances as Avery Baltus on the television series Party of Five. He also guest starred in an episode of Quantum Leap and appeared as Superintendent Hazen on several episodes of Dr. Quinn, Medicine Woman.
In the 1990s, Sloyan also made frequent appearances in the Star Trek spin-offs The Next Generation, Deep Space Nine and Voyager.