Sa4 or SA-4 may refer to:

• Sa4 (Luwian hieroglyph), the 4th of 7 hieroglyphs for Sa in Hieroglyphic Luwian
• Sa4 (rapper), German rapper, member of band 187 Strassenbande
• Saturn I SA-4, an Apollo program launch
• 2K11 Krug, a Russian surface-to-air missile system

• Building and Construction Trades Department, AFL–CIO
• Building and loan
• Building and loan association
• Building and Wood Workers International
• Building and Wood Workers' International
• Building and Wood Workers International - BWI
• Building Architect Tool
• Building a Socialist Work Ethic
• Building at 10108 Northeast 1st Avenue
• Building at 107 Northeast 96th Street
• Building at 121 Northeast 100th Street
• Building at 145 Northeast 95th Street
• Building at 253 Northeast 99th Street
• Building at 257 Northeast 91st Street
• Building at 262 Northeast 96th Street
• Building at 273 Northeast 98th Street
• Building at 276 Northeast 98th Street
• Building at 284 Northeast 96th Street
• Building at 287 Northeast 96th Street
• Building at 310 Northeast 99th Street
• Building at 353 Northeast 91st Street
• Building at 357 Northeast 92nd Street
• Building at 361 Northeast 97th Street
• Building at 384 Northeast 94th Street
• Building at 389 Northeast 99th Street