HS-121 or Hs-121 can refer to:

• Hawker Siddeley HS-121 Trident, a British airliner
• Henschel Hs 121, a German trainer aircraft

• Stanley United
• Stanley United F.C.
• Stanley Uys
• Stanley v Georgia
• Stanley Vickers (disambiguation)
• Stanley v. Illinois
• Stanley Vivian Bacon
• Stanley Vollant
• Stanley v. State of Illinois, 1972
• Stanley Wagoner
• Stanley Walker (disambiguation)
• Stanley Wallage
• Stanley Walpole
• Stanley Walsh
• Stanley Walter Alexander
• Stanley Walters
• Stanley Washington
• Stanley Wasserman
• Stanley Watson
• Stanley Weber
• Stanley Weston (rugby league)
• Stanley Weyman (disambiguation)
• Stanley Whitaker
• Stanley Whitford
• Stanley Whiting