S series or Series-S or variation, may refer to:
Transportation
- Bedford S series, trucks
- Chevrolet S-series, pickup trucks
- GMC S-Series, school bus
- International S series, trucks
- International S series (bus chassis)
- S series (Toronto subway), rapid transit rolling stock
- Saturn S series, compact cars
- Waco S series, biplanes
- S series of BMW engines
- S series services of Calcutta State Transport Corporation
- S series, Meguro motorcycles
- S-series Toyota LiteAce, vans
Technology
- S-Series (rocket family), funded by the Japan Aerospace Exploration Agency
- Fujifilm FinePix S-series
- Minolta Vectis S series, cameras
- Lenovo IdeaPad S series
- Samsung Galaxy S series, smartphones and tablets
- Sony Vaio S series, netbooks
- Sony Walkman S Series, portable media players
- S series, Acer Aspire laptops
- Apple S series processors used in the Apple Watch
- S series, Lenovo ThinkPad laptops
- S series of HP ProBook, notebook computers
- Sony Ericsson S series, a series of cell phones
- S series Force10, network switches
- Xbox Series S, 9th generation Xbox videogame console from Microsoft
Other uses
- Ibanez S series, guitar
- S-series Dungeons & Dragons modules, four modules of the fantasy tabletop role-playing game
- S-Series of ILS specifications, specifications for integrated logistics support
- S series, supplement to the Official Journal of the European Union