Idea A Day was a web-based ideas bank founded in London in August 2000 by music executive David Owen, advertising executives Chas Bayfield and Becky Clarke, and teacher Rupert Kaye in partnership with the web development company Fortune Cookie.

One idea published on Idea A Day is Flipside TV, a live TV review show in which a host and three guests watched television live as it happened and recommended to viewers what they could or should be watching on the other side.

The TV show ran in the UK on Channel 4 and Paramount Comedy.

In August 2011, the site's editor Chas Bayfield posted an urgent request for help.

The site ceased publishing ideas in 2015 but was revived on Twitter in February 2020.