Words by letter S
- Social rights, see Social entitlements
- Social security systems and social protection
- Socrates
- Soft law
- Solana, Javier (1942 - )
- Solbes Mira, Pedro (1942 - )
- Solemn Declaration on European Union
- Solidarity clause
- Solidarity Fund
- SOLVIT
- SOS-Democracy
- Sovereignty
- Spaak, Paul-Henri (1899 - 1972)
- Space
- Spain