20 to One (known as 20 to 1 before 2016) is an Australian television series on the Nine Network from 2005, that counts down an undefined "top 20" of elements or events of popular culture, such as films, songs, or sporting scandals. The format mixes archival footage of the listed events with comments from various Australian celebrities.

Originally the show was hosted by Bud Tingwell and narrated by David Reyne; the pair were replaced by Bert Newton as host for the second season. The series was rebooted by the Nine Network and returned for its eleventh season on 31 May 2016 with new hosts, Australian radio presenters Fitzy and Wippa. From 2017, the show was hosted by Erin Molan and Dave Thornton.