- Hines and Hines, Inc.1
- Hirsch, Alexander1
- Hirshman, Irving J.2
- Hitlin, Paul S.1
- Hodgman1
- Hofka Realty Corp.1
- Hohauser, William I.22
- Holiday Holding, Inc.1
- Holland, Jack J.2
- Hollyday and Ives, Inc.20
- Home Specialists1
- Homecrest Development Corp.1
- Homefinders, Ltd.1
- Hood, Raymond2
- Horace Ginsbern and Associates28
- Horace I. Kaplan and Son1
- Horace S. Ely and Co.5
- Horn and Burke4
- Hotel Pierre, Inc.1
- House and Apartment Sales Corp.1
- Hovan Realty Corp.1
- Howard Ecker and Co.1
- Howard P. Hoffman Associates1
- Höltzel, Hieronymus, active 1500-15251
- Hubbell-Klapper and Hubbell1
- Huberth and Huberth, Inc.2
- Hudon Towers Corp.2
- Hudson Heights Apartments, Inc.1
- Hudson Manor Avenue Apartments, Inc.2
- Hudson Parkway Corp.1
- Hull Builders, Inc.1
- Huntley Estates, Inc.1
- Hunts Lane Realty Co., Inc.1
- Hupfel, Jogn G.1
- Hurley and Ferinella1
- I.G. Wolf-R.A. White, Inc.1
- I.M. Pei and Associates1
- ILE Realty Corp.1
- Ifill and Johnson1
- Imarata, Lawrence1
- Imperial Realty Corp.2
- Imperial Square Associates2
- Income Properties, Inc.1
- Investors in America, Inc.1
- Inwood Country Club1
- Ipswich Development Corp.2
- Irmax Realty Corp.1
- Irvin House Inc.1
- Irving Berger and Associates1
- Irving Kaskel and Sons1
- Irving Seelig and Son2
- Isacowitz, Murray D.1
- Iser, Gustave W.15
- Isidore Rosen and Sons, Inc.2
- Ismac Realty Corp.1
- Ithaca Building Corp.1
- J. Friedman Construction Co., Inc.1
- J. Marmaros Construction Corp.1
- J. Perlbinder and Sons1
- J. Rodman Realty Co.2