The Jersey City Free Public Library is home to two unique collections, The New Jersey Room and Biblioteca Criolla.

Biblioteca Criolla is the home to the most extensive collection of materials in Spanish in the state of New Jersey. The collection includes reference books, fiction and literature for adults and children, newspapers, magazines and audio books.

The New Jersey Room is a collection of materials about New Jersey with an emphasis on Jersey City and Hudson County. The collection, numbering about 20,000 volumes, includes both current and historical information. In addition to books, the New Jersey Room has a complete collection of all published Jersey City/Hoboken city directories dating from 1849 to 1925; an index for the Jersey Journal for the years 1912-1954 and 1969 to the present, a picture collection of over 13,000 images; hundreds of historic and contemporary maps; over 150 periodicals; manuscript collections; and several thousand topical files.