- Central Synagogue (New York, N.Y.)1
- Century Association (New York, N.Y.)3
- Century Association (New York, N.Y.). Committee on Admissions1
- Chalmers, George, 1742-18251
- Chamber of Commerce (Queens, New York, N.Y.)1
- Chamber of Commerce of the United States of America1
- Chamberlain, Alexander Francis, 1865-19141
- Chambers, Julius, 1850-19202
- Champney, James Wells, 1843-19031
- Chandler, Charles Frederick, 1836-19252
- Chapin Home for the Aged and Infirm (New York, N.Y.)1
- Chapin, Anna Alice, 1880-19201
- Chapin, Robert Coit, 1863-1
- Chapman, J. G. 1808-18891
- Chappell, Warren, 1904-19911
- Charity Organization Society of the City of New York1
- Charity Organization Society of the City of New York. Tenement House Committee1
- Charles Scribner's Sons1
- Charter Revision Commission of the City of New York1
- Chasmar-Winchell Press1
- Chastellux, François Jean, marquis de, 1734-17881
- Chauncey Real Estate Co1
- Cheetham, James, 1772-18101
- Chemical Corn Exchange Bank1
- Chester, Alden, 1848-19341
- Child, Charles G1
- Childe, Cromwell2
- Children's Aid Society (New York, N.Y.)1
- Children's Writers and Artists Collaborative1
- Childs, Richard S. 1882-19781
- China. Zong li ge guo shi wu ya men1
- Chisholm Bros3
- Chittenden, S. B. 1814-18892
- Chorley, E. Clowes 1865-19491
- Christensen, K1
- Church, Elihu Cunyngham1
- Church, Frederick S. 1842-19241
- Churchill, Allen, 1911-19884
- Churchill, Winston, 1874-19651
- Citibank (New York, N.Y.)2
- Citizen of Port-Royal in Jamaica1
- Citizens Budget Commission (New York, N.Y.)1
- Citizens Housing and Planning Council (New York, N.Y.)7
- Citizens Union (New York, N.Y.)4
- Citizens Union (New York, N.Y.). Bureau of City Betterment1
- Citizens Union (New York, N.Y.). Sub-Committee on Zoning1
- Citizens Union of the City of New York1
- Citizens' Association of New York9
- Citizens' Association of New York. Council of Hygiene and Public Health1
- Citizens' Committee (New York, N.Y.)1
- Citizens' Committee of the Borough of the Bronx1
- Citizens' Protective League, New York1
- City Club of New York5
- City History Club of New York2
- City Improvement Society (N.Y.)1
- City Missionary Society of the Reformed Protestant Dutch Church (New York, N.Y.)1
- City Title Insurance Company2
- City University of New York. Graduate School and University Center3
- Civil Service Commission of the City of New York1
- Clapp & Company, New York1