- Congressional Rural Caucus (U.S.)1
- Congressional Steel Caucus (U.S.)1
- Congressional Youth Leadership Council1
- Connally, John Bowden, 1917-19931
- Connally, Tom, 1877-19633
- Conrad, Kent, 1948-5
- Consensus Marketing5
- Consolidation Coal Company1
- Consumer Federation of America2
- Conversion Films1
- Conyers, John, Jr., 1929-20191
- Cookie Monster (Fictitious character)1
- Cooley, Harold D. (Harold Dunbar), 1897-19741
- Coons, A. T.1
- Cooper, John Sherman, 1901-19913
- Corman, James C. (James Charles), 1920-20001
- Cornwell, David L., 1945-20121
- Costle, Douglas1
- Cottington Mari, Inc.6
- Cotton, Norris, 1900-19891
