BYS may refer to:

• "B.Y.S.", a song from the album Daily Operation by Gang Starr
• Baggio–Yoshinari Syndrome, a tick-borne disease found in Brazil
• Boston Youth Symphony

• 1966 Major League Baseball draft
• 1966 Major League Baseball season
• 1966 Maryland gubernatorial election
• 1966 Maryland Terrapins football team
• 1966 Massachusetts gubernatorial election
• 1966 Mauritanian presidential election
• 1966 Meistaradeildin
• 1966 Mestaruussarja
• 1966 Miami Dolphins season
• 1966 Miami Hurricanes football team
• 1966 Michigan State Spartans football team
• 1966 Michigan Wolverines football team
• 1966 Minnesota Golden Gophers football team
• 1966 Minnesota gubernatorial election
• 1966 MLB Draft
• 1966 MLB season
• 1966 Mosport Can-Am
• 1966 movie
• 1966 Myers Brothers 250
• 1966 NAIA Division I Men's Basketball Tournament
• 1966 NASCAR Grand National Series
• 1966 NASCAR Sprint Cup Series
• 1966 NBA All-Star Game
• 1966 NBA expansion draft
• 1966 NCAA College Division Basketball Tournament