William David Daniels (born March 31, 1927) is an American actor who is known for his television roles, notably as Mark Craig on the drama series St.

At the suggestion of Howard Lindsay, co-author of Life with Father, who recommended he use the GI Bill to attend a college with a good drama department, Daniels enrolled at Northwestern University.

[citation needed] Daniels portrayed strict but loving educator George Feeny at John Adams High School in Boy Meets World from 1993 to 2000.

In addition to the previously mentioned 1967 superhero sitcom Captain Nice, he was a regular on the 1970s TV series Freebie and the Bean and The Nancy Walker Show.

[citation needed] A familiar character actor, he has appeared as a guest star on numerous TV comedies and dramas, including Soap, The Rockford Files, Quincy, M.E., Kolchak: The Night Stalker, and many others.

In 2012, Daniels appeared in the ninth season of Grey's Anatomy as Dr. Craig Thomas, an unlikely mentor to the character of Dr. Cristina Yang played by actress Sandra Oh.

His character, Dr. Thomas, died in the operating room while performing a procedure to repair a heart defect midway through the season, which forced Yang to move back to Seattle.

[14] Daniels has been married to actress and fellow Emmy Award winner Bonnie Bartlett since June 30, 1951; at 73 years, it is the longest active Hollywood marriage as of July 2024.

They adopted two sons: Michael, who became an assistant director and stage manager in Los Angeles, and Robert, who became an artist and computer graphics designer based in New York City.

[18] Daniels refused the 1969 Tony Award nomination for Featured Actor in a Musical in 1776 due to his insistence that the part of John Adams was a leading role rather than supporting.

Elsewhere, won Emmy Awards on the same night (Bartlett for Supporting Actress in a Drama Series), becoming the first married couple to accomplish the feat since Alfred Lunt and Lynn Fontanne in 1965 for a production of The Magnificent Yankee for the Hallmark Hall of Fame.