SDP
- Birds in the Trap Sing McKnight
- Communist Party of Kenya
- DSP (disambiguation)
- Democratic Socialist Party (disambiguation)
- PDS (disambiguation)
- Party of Democratic Socialism (disambiguation)
- SDP (duo)
- SPD (disambiguation)
- San Diego Padres
- Sand Point Airport
- Sandplace railway station
- Scenario Design Power
- Scha Dara Parr
- School District of Philadelphia
- Semidefinite programming
- Service Design Package (ITIL)
- Service data point
- Service delivery platform
- Service discovery protocol
- Session Description Protocol
- Sherdukpen language
- Singapore Democratic Party
- Single-dealer platform
- Social Democratic Party
- Social Democratic Party (Andorra)
- Social Democratic Party (Japan)
- Social Democratic Party (Latvia)
- Social Democratic Party (New Zealand)
- Social Democratic Party (Serbia)
- Social Democratic Party (Serbia, 2002)
- Social Democratic Party (UK)
- Social Democratic Party (UK, 1988–1990)
- Social Democratic Party (UK, 1990–present)
- Social Democratic Party in the GDR
- Social Democratic Party of America
- Social Democratic Party of Bosnia and Herzegovina
- Social Democratic Party of Croatia
- Social Democratic Party of Finland
- Social Democratic Party of Germany
- Social Democratic Party of Montenegro
- Social Democratic Party of Serbia
- Socialist Democrat Party
- Socialist Democratic Party (Canada)
- Socialist Democratic Party (Chile)
- Socialist Democratic Party (Turkey)
- Socialist Democratic Party (disambiguation)
- Society of Decorative Painters
- Sockets Direct Protocol
- Software-defined perimeter
- Stardust Pictures
- State Domestic Product
- Stephen Dale Petit
- Stoomtrein Dendermonde-Puurs
- Stuart Price
- Substantive due process
- Sudeten German Party
- Surinamese Democratic Party