- J.G. Haft and Co., Inc.24
- J.G. MacInnis Co.2
- J.H. Taylor Construction Co., Inc.4
- J.H. Taylor Management Co., Inc.10
- J.I. Sopher and Co., Inc.50
- J.M.C. Realty Corp.1
- J.P. Lieberman and Son, Inc.2
- J.W. Modlin Construction Co., Inc.1
- JC Organization1
- Jacar Building, Inc.1
- Jacfred Apartments, Inc.2
- Jack Hegarty Co., Inc.1
- Jack Resnick and Son14
- Jackder Construction Corp.1
- Jackson Construction Corp.1
- Jackson Fillmore Corp.1
- Jackson Heights-Mount Vernon Corp.1
- Jackson House Corp.1
- Jackson Management Corp.4
- Jackson Surrey Corp.1
- Jacksonian Apartments, Inc.1
- Jacmar Operating Corp.1
- Jacob D. Berg and Sons1
- Jacoby Construction Co.1
- Jaffe, Sheldon A.1
- Jahil Realty Corp.1
- Jamaica Ave. and 138th Place Corp.1
- Jamer Realty Corp.1
- James Charles Stewart, Inc.26
- James D. Landauer Associates, Inc.1
- James Felt and Co., Inc.3
- James Felt-Huberth and Huberth, Inc.1
- James N. Wells' Sons, Inc.10
- James Realty Co.6
- James Stewart and Co., Inc.2
- Janent Holding Corp.1
- Janos-Langer6
- Jardwo Construction Corp.1
- Jasi Realty Corp.1
- Jay R. Braus Co.4
- Jaysons Holding Corp.1
- Jedsor Realty Corp.1
- Jefferson Construction Corp.1
- Jefflan Realty, Inc.1
- Jerelyn Realty Corp.1
- Jerome Building Corp.1
- Jerome Equities, Inc.1
- Jerry Spiegel Associates2
- Jewel Estates, Inc.2
- Jo-Ann Realty Corp.1
- Joan Building Corp.1
- Jochas Corp.1
- Joedbur Realty Corp.2
- John Avlon Real Estate1
- John Avlon, Inc.35
- John E. Warner and Sons, Inc.2
- John F. James and Son, Inc.1
- John H. Carpenter Jr., Inc.5
- John Hancock Mutual Life Insurance Co.1
- John J. Reynolds Management Co., Inc.2