"Dancing with the Stars" Season 20 premiered on March 16, 2015, and concluded on May 19, 2015, for the American version of the show.
If the interest is in the current or upcoming season to mark the 20th anniversary of the show overall, the 34th season (which is the 20-year anniversary season) is premiering on Tuesday, September 16, 2025, at 8 PM ET on ABC with a two-hour episode.
So, Season 20 originally aired in 2015, and the 20th-anniversary celebration is happening with Season 34 airing now in 2025.
