- Citadel Hall, Inc.1
- City Builders, Inc.1
- City Center Organization7
- City Investing Co.4
- Clarciam Realty Corp.1
- Clarence Lilien and Associates1
- Clarence R. Knickman, inc.6
- Claridge Realty Corp.1
- Clarkson Development Corp.2
- Clawson, Harry M.8
- Clayton Apartments, Inc.8
- Clement E. Merowit and Co.1
- Clifford Apartments, Inc.5
- Clifton Manor Apartments, Inc.1
- Climcheck, S.1
- Clinton Housing Association1
- Cloverton Corp.2
- Coates Realty Corp.4
- Code Holding Corp.1
- Cohen Brothers Realty10
- Cohen Brothers Realty and Construction Corp.11
- Cohn Brothers12
- Cohn, Herman M.1
- Cole, H.M.1
- Collins, Tuttle and Co.16
- Colonial Towers, Inc.2
- Columbia-Clark Corp.6
- Commonwealth Syndicate, Inc.1
- Compton Estates, Inc.1
- Conco Realty Corp.1
- Concord Hall, Inc.1
- Concord Village Co.3
- Concourse Building Corp.1
- Concourse Crescent Corp.1
- Concourse Development, Inc.1
- Concourse Properties, Inc.1
- Concourse and 181st Street Corp.1
- Construction and Development Corp. of New York1
- Convent Gardens, Inc.1
- Cooper-Bregstein Realty Co.9
- Coral Gardens, Inc.1
- Cord-Meyer Development Co.12
- Cornish Arms, Inc.1
- Coronet Realty, Inc.1
- Cosmopolitan Associates1
- Court and Remsen Building Corp.10
- Crandall, Edward H.1
- Crausman, I.L.20
- Creston Building Corp.1
- Creston Realty Corp.1
- Crislou Realty Corp.1
- Crocheron Gardens, Inc.1
- Cross & Brown Company1
- Cross Properties, Inc.24
- Cross and Brown Co.10
- Cross and Cross5
- Crotona Building Corp.1
- Cruikshank Co.11
- Culver Associates, Inc.4
- Culver, Hollyday and Co., Inc.16