30 may refer to:

• 30 (number), the natural number following 29 and preceding 31
• one of the years 30 BC, AD 30, 1930, 2030

• Zinc, a transition metal in the periodic table
• 30 Urania, an asteroid in the asteroid belt

• 30 (Harry Connick Jr. album), 2001
• 30 (album), by Adele, 2021
• 30 (Sungjin album), 2024
• 30, a 1997 album by Laurent Garnier
• 30, a 2004 album by James Yorkston
• 30, a 2006 album by Jerusalem, also called Tretti
• 30, a 2014 compilation album by Modern Talking
• 30, a 2016 album by Trio da Paz
• "Thirty", a 2019 album by Strings
• "Thirty", a song by Karma to Burn from the album Wild, Wonderful Purgatory, 1999
• "30", a 2021 song by Bo Burnham from the special Bo Burnham: Inside
• "30", a 2021 song by Pop Smoke from the album Faith

• "-30-", traditionally used by journalists in North America to indicate the end of a story
• -30- (film), 1959, also released as Deadline Midnight
• 30 (Law & Order: Criminal Intent), an episode of the television series Law & Order: Criminal Intent
• –30– (The Wire), the series finale of the HBO original series The Wire
• 30 (tennis), a score indicating two points won
• 30 caliber
• Tatra 30, an automobile produced by Tatra
• Renault 30, an executive hatchback produced by Renault

• The Thirty (disambiguation)
• XXX (disambiguation), Roman numeral representation of 30
• 30 Roc, American music producer
• List of highways numbered 30