S
- Sage, Russell (1816–1906), CM&StP.
- St. Clair-Abrams, Alexander (1845–1931), TO&A.
- Saunders, Stuart T. (1909–1987), N&W 1958-1963, PRR 1963–1968, PC 1968-1970.
- Scannell, Daniel T., LIRR 1981.
- Schaff, Charles E., MKT 1923-1926.
- Schieffer, Kevin V., DME 1996-2008.
- Schlager, Walter L., Jr., LIRR 1969-1976.
- Schmiege, Robert, CNW.
- Schoonmaker, James M., P&LE.
- Scott, I. Barry, CPR -1995.
- Scott, Thomas A. (1823–1881), UP 1871-1874, PRR 1874–1880.
- Scranton, George W. (1811–1861).
- Sease, Ralph E., NYSW 1955-1963.
- Seger, C. B., UP 1918-1919.
- Segień, Mikołaj, SKM -present.
- Sengeløv, Keld (d. 2006), DSB -2006.
- Sengoku, Mitsugu, South Manchuria Railway 1928-1931.
- Sharp, Thomas R., LIRR 1877-1881.
- Shaughnessy, Thomas George (1853–1923), CPR 1899–1918.
- Sheffield, Bill (born 1928), ARR 1997-2001.
- Sheffield, Joseph Earl (1793–1882), Northampton Railroad.
- Sherwood, Henry (1813–1896), W&L.
- Shoemaker, Kent, D&H 1978-1982.
- Shoener, Arthur, KCS 2005–present.
- Shoup, Paul, SP 1929-1932.
- Shumate, Stuart, RFP 1961-1981.
- Sinclair, Ian David (1913–2006), CPR 1969-1981.
- Sloan, Matthew S., MKT 1933-1945.
- Smith, Alfred H. (died 1924), NYC.
- Smith, Charles E. RDG -1866.
- Smith, John Gregory (1818–1891), NP 1866-1872.
- Smucker, David E., LIRR 1949-1950.
- Snow, John W. (born 1939), B&O 1985-1986, CSXT 1986-1988.
- Spencer, Samuel (1847–1906), SOU 1894-1906.
- Speyer, Edgar (1862–1932), UERL 1906-1915.
- Sprague, Lucian (1882–1960), M&StL 1935-.
- Sproule, William, SP 1911-1918 and 1920-1928.
- Stamp, Josiah (1880–1941) LMS 1926-.
- Stanley, Albert, Lord Ashfield (1874–1948), UERL 1920-1933, LPTB 1933-1947.
- Stanford, Leland (1824–1893), CP 1861-1868, SP 1868-1893.
- Stauffer, Grant (died 1949), CGW 1948-1949.
- Stephen, George (1829–1921), CPR 1881-1888.
- Sterzing, Carl B., D&H 1972-1977.
- Stickney, Alpheus Beede (1840–1916), CGW 1883-1909.
- Stilwell, Arthur Edward (1859–1928), KCP&G -1899, KCM&O.
- Stinson, William (born 1935), CPR 1981-1990.
- Stockdale, Fletcher (c. 1823-1890), Indianola Railroad.
- Stoddard, A. E., UP 1949-1965.
- Storey, William Benson (1857–1940), ATSF 1920–1933.
- Strong, Henry, ATSF 1873–1874.
- Strong, William Barstow (1837–1914), MC -1876, ATSF 1881–1889.
- Swinburn, Charles (born 1942), RailAmerica.
- Swartz, W. John, ATSF 1986–1989.
- Symes, James H., PRR 1954-1963.
Read more about this topic: List Of Railroad Executives