Z1, Z-1, or Z.1 may refer to:

• Z.1 or the Flow of Funds, a U.S. government fiscal report
• Z.1, an anti-tank barrier known as Admiralty scaffolding
• Z-1 (band), a Japanese idol group
• Z1 class Melbourne tram
• Z-1 (comics), a DC comics character
• Z1 (computer), a mechanical computer designed by Konrad Zuse from 1935 to 1936
• Z1 Battle Royale, a 2018 video game
• Z1 TV, a Czech TV channel
• Z1 Zagrebačka Televizija, a Croatian regional television network
• Z-1 Suit, an experimental space suit
• AEG Z.1, a German aircraft built before World War I from Zagreb
• BMW Z1, a two-seat roadster
• German destroyer Z1 Leberecht Maass
• Great Northern Railway Z-1 class, a class of electric locomotives used by the Great Northern Railway (U.S.)
• NER Class Z1, a class of British steam locomotives (redesignated class Z in 1914)
• Goodyear Z-1, N-class blimps of the U.S. Navy
• HZ-1 Aerocycle, an experimental U.S. Army flying platform of the 1960s
• Kawasaki Z1, a motorcycle
• Sony HVR-Z1, a HDV format camcorder manufactured by Sony
• Sony Xperia Z1, a smartphone manufactured by Sony
• Zork I, an interactive fiction computer game
• the train code for high-speed train between Shanghai and Beijing
• Z1 Digital Studio, an international digital product studio based in Seville