- Hirth-Kraus Company1
- Hoberman and Wasserman1
- Hoffman Corr MF'G Co.2
- Hoffman, F. Burrall, Jr.5
- Hohauser, William I.2
- Holbrook Brothers, Inc.2
- Holbrook, Merrill & Stetson1
- Holland, Jack J.1
- Holland-Brecher Building Corp.3
- Holliswood Hills Apartments, Inc.1
- Holyoke Belting Co.1
- Homebound Building Corp.1
- Homer Ramsdell & Co.1
- Hood, Godley, and Fouihoux1
- Hood, Raymond12
- Horace Ely and Co.1
- Horace Ginsbern and Associates41
- Horowitz, Stanley L.3
- Hosford & Ketcham2
- Hotel Boyer1
- Hotel Pierre, Inc.7
- Hotel Walton1
- Hotel Westminster1
- Hotpoint1
- House and Apartment Sales Corp.14
- Housing and Redevelopment Board of The City of New York1
- Howard Hotel3
- Howard National Bank of Boston1
- Howard Sanger & Co.1
- Howell & Saxtan1
- Howlett Brothers1
- Hudson Manor Avenue Apartments, Inc.5
- Hunter Gardens, Inc.3
- Huntington, Hopkins & Co.1
- Huttig Sash & Door Co.1
- Hutzler Brothers1
- I. B. Williams & Sons1
- I. Newman & Sons2
- I. Orlian and Sons5
- I.G. Wolf-R.A. White, Inc.1
- I.J. Associates, Inc.1
- I.J. Realty Corp.1
- I.M. Pei and Associates14
- Ide, Felt & Hall1
- Iler & Co.2
- Imarata, Lawrence1
- Imperial Paste Mfg. and Merchantile Company1
- Imperial Square Associates10
- Imperial Woolen Company1
- Income Properties, Inc.11
- Independence Terrace Corp.1
- Indianapolis Saddlery Co.1
- Industrial Real Estate Development2
- Interboro Realty Co.9
- International Coffee Company1
- International Hotel1
- International Stock Food Company1
- Ipswich Development Corp.16
- Irving & Casson1
- Irving House1