Family spokeswoman Lori De Waal told the Associated Press that Hillerman had passed away in his home in Houston, but the cause of death has not yet been determined.
Hillerman's other credits include The Betty White Show, Valerie's Family, Simon & Simon, Murder, She Wrote and One Day at a Time. For his role on Magnum, P.I., Hillerman received four Emmy nominations for Outstanding Supporting Actor in a Drama Series, one of which he won in 1987. He also received five Golden Globe nominations for Best Supporting Actor - Series, Miniseries or Television Film, one of which he won in 1982.
This unfortunate news comes on the heels of CBS' recent announcement that a Magnum, P.I reboot is in the works from Peter Lenkov.