S
- Make (Years In Operation) -- Plant
- Models
- S and S (1924-1929) -- Cincinnati, OH
- No models named
- St. Louis (1921-1925) -- St. Louis, MO
- No models named
- Saxon (1913-1922) -- Detroit, MI
- Y-18-T
- Duplex 125
- Sayers (1917-1924) -- Cincinnati OH
- No models named
- Schuler () -- Milwaukee, WI
- No models named
- Scott-Newcomb Steam (1920-1921) -- St. Louis, MO
- No models named
- Scripps-Booth (1912-1922) -- Detroit, MI
- B
- F
- Seneca (1917-1924) -- Fostoria, OH
- L
- R-21
- 50
- L-2
- Shaw (1920-1921) -- Chicago, IL
- Colonial
- Sheridan (19119-1921) -- Muncie, IN
- Four
- Simms (1920) -- Atlanta, GA
- No models named
- Singer (1914-1920) -- New York, NY
- Six
- Twelve
- Skelton (1920-1922) -- St. Louis, MO
- 35
- Spencer (1921-1922) -- Los Angeles, CA
- No models named
- Standard (1914-1923) -- Butler, PA
- I
- II
- Stanley Steam (1899-1927) -- Newton, MA
- 735A
- 735B
- 735C
- 735D
- 735
- 740
- S-V
- 762
- 770
- Star (1922-1928) -- Elizabeth, NJ
- Four
- F
- F-25
- Six
- M-2
- Stearns-Knight (1901-1929) -- Cleveland, OH
- SKL-4
- SKL-6
- Four
- Six
- 6-C
- 6-S
- D-6-85
- G-8
- F6-85
- H
- J
- M6-85
- H
- J
- M6-80
- N6-80
- H8-90
- J8-90
- H8-90
- Stephens (1916-1924) -- Freeport, IL
- 82
- 83
- 84
- 84B
- 84C
- 85
- 86
- 92
- 92B
- 93
- 94
- 94A
- 94B
- 95
- 96
- 96A
- 97
- 98
- 12
- 15
- 16
- 16A
- 18
- 24
- 26
- 27
- 124
- 154
- 164
- 184
- 244
- 164A
- 274
- Sterling-Knight (1920-1926) -- Cleveland, OH
- Six
- Stevens-Duryea (1901-1927) -- Chicopee Falls, MA
- E
- G
- Stork-Kar (1919-1921 -- New York, NY
- No models named
- Stout Scarab (1932-1936) -- Detroit, MI
- No models named
- Studebaker (1902-1942) -- South Bend, IN
- EG
- EH
- EJ to EM
- EP to ES
- EU
- EW
- GE
- GB
- FA
- GH
- FB
- GJ
- FD
- FH
- FE
- 53
- GL
- FC
- 54
- 61
- 70
- 80
- 90
- 55
- 62
- 71
- 91
- 56
- 73
- 82
- 92
- A
- Special A
- B
- C
- 1A/2A
- 1B
- 1C
- 3A/4A
- 2C
- 5A/6A
- 3C
- 7A
- 8A
- 4C
- G
- 9A
- 5C
- 2-G
- 10-A
- 6-C
- 3-G
- 11A
- 7C
- 4-G
- 12-A
- 8-C
- Stutz (1911-1935) -- Indianapolis, IN
- H
- K
- Special Six
- Speedway Four
- 693
- 694
- 695
- Vertical Eight
- BB
- M
- MA
- MB
- LA
- LAA
- SV-16
- DV-32
- Sun (1921-1922) -- Toledo, OH
- Four
- Supreme (1917-1922) -- Cleveland, OH
- No models named