Following this, he starred as songwriter Cyrus DeBarge in the Disney Channel film Let It Shine (2012), and Noah on the AMC drama television series The Walking Dead (2014–15).

[6] He later starred in Little Bill as the voice of Bobby, briefly replacing Devon Malik Beckford in 2000, and played himself (or an eponymous character, "Tyler") on the PBS series Sesame Street from 2000 to 2005.

[9] He also played the lead role of Cyrus DeBarge in the Disney Channel film Let It Shine[10] alongside Coco Jones, Trevor Jackson, and Brandon Mychal Smith.

The film premiered on June 15, 2012, and his songs "Don't Run Away," "Me and You," "Guardian Angel," "Let It Shine" and "Moment of Truth" all received airplay on Radio Disney.

[12] In 2014, Williams starred in Justin Simien's independent film Dear White People as Lionel Higgins,[13] and was cast as the recurring character Noah on the television series The Walking Dead.

[18] In 2019, Williams was cast as Jake in The Wedding Year, a teen romantic comedy film directed by Robert Luketic and starring Sarah Hyland, Jenna Dewan, Matt Shively, and Anna Camp.