Clifford the Big Red Dog

John Ritter voiced Clifford in every episode. By the time the series ended production and the subsequent film Clifford's Really Big Movie were completed, Ritter was back on ABC's prime time schedule, starring in 8 Simple Rules. Ritter's death on September 11, 2003, came ten days after the debut of Clifford's Puppy Days (it is often mistakenly cited as the reason the spin-off was created in lieu of a third season).

Though production of Clifford ended before Ritter's death, voice actors for the main characters have reprised some of their roles for the Ready to Learn PBS Kids PSAs. Clifford's Really Big Movie served as the series finale, while Clifford's Puppy Days still continued to air until its cancellation in 2006.

On May 16, 2018, Scholastic announced a reboot of the series, which was announced on December 5, 2019, to be released on December 6, 2019, on Amazon Prime Video and December 7, 2019, on PBS Kids, starring Adam Sanders as the new voice of Clifford. PBS Kids continued to air reruns of the 2000 series until October 2, 2022. Very few PBS member stations still continue to carry the series.

As of 2021, the show is currently distributed worldwide by 9 Story Media Group.