The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates various forms of public transit services—bus, subway and elevated rail, commuter rail, light rail and electric trolleybus—that serve 3.9 million people in five counties in and around Philadelphia, Pennsylvania, United States. SEPTA also manages construction projects that maintain, replace, and expand infrastructure and rolling stock.

Septa may refer to:

• The plural of septum, in anatomy, a wall of tissue dividing a cavity (e.g., in the nose)
• Septa (gastropod), a gastropod genus in the family Ranellidae
• Septa (coral), stony ridges forming part of the corallites of corals
• SEPTA, the Southeastern Pennsylvania Transportation Authority