He reunited with his former Brady costars in the holiday TV movie A Very Brady Christmas (1988).Before the Brady Bunch series, he had had some small television roles, including an appearance on the first season of Mannix, in a 1967 episode called "Coffin for a Clown". He is known for playing Peter Brady on the 1970s series The Brady Bunch.He has since gone on to become a successful businessman and enjoyed a semi-resurgence in the public eye with television appearances in the 2000s. After the end of his Brady Bunch appearances, Knight's acting career consisted mostly of making guest appearances on other television shows (Happy Days, The Love Boat), and occasional film roles (Just You and Me, Kid, Curfew, Good Girls Don't, The Doom Generation, and Nowhere).I️ have known, loved, and admired David Cassidy for 48 out of my 58 years. There were times in the mid-1970s when he would come over to my house and we even started writing a song together. Our shows were both on Friday nights and deep down I dreamt of being a Partridge. David Cassidy's Keith was one of my favorite TV characters. The man entertained me during my childhood and even years later: https://t.co/678DU7q Txh — Kevin Smith (@That Kevin Smith) November 22, 2017 Heartbroken over the passing of #David Cassidy.
Knight won the show and donated the proceeds (,000) to his selected charity, Zero Population Growth.
In 1988, Knight, a self-described "geek", left acting to pursue a business career in the computer industry.
He got a job as an accountant sales manager for Martec, Inc.
We’ve been through a lot together and he was always there for me. he was always so kind to me - such a pleasure to have had him on my show… I was lucky to get to know the sweet & very funny real David as an adult & I still wanted to be him.
— Tom Arnold (@Tom Arnold) November 22, 2017 My uncle David Cassidy has sadly passed away tonight…
The two have remained close friends since their Brady Bunch days, and Williams appeared several times on My Fair Brady.