Nassau County, New York Genealogy Guide

Nassau County, New York (Map It) created on 1899 from Queens County. The county was named in honor of the Princes of Orange-Nassau ruled the Netherlands when Long Island was a Dutch colony .

Nassau County is bordered by Suffolk County (east), Queens County (west).

Nassau County Cities and Towns include Mineola, Glen Cove, Long Beach, Hempstead, North Hempstead, Oyster Bay.

Nassau County, New York Courthouse Records

Nassau County, New York Courthouse
Nassau County, NY Courthouse

The Nassau County Courthouse is located in Mineola, New York. Also contact local Town Clerks. They are responsible for vast amounts of local information from deeds, property transfers, and genealogical materials. Research on place and road names, the history of property transfers and much more are available through your Town Clerk. They are a tremendous resources. Learn More About State of New York Court, Tax, Land and Probate Records.

Please contact the each clerk's department to confirm mailing address, hours, fees and other information before visiting or requesting information because contact information sometimes changes.  The Clerk's Office DOES NOT DO RESEARCH.  The documents are available to interested parties, barring confidential issues.  Most staff will assist people in finding the materials, but it is up to the individual to do the research.

The following dates indicates what vital, land, probate, and court records are in Nassau county. The date listed for each category of record is usually the earliest registration filed. The earliest date does not indicate that there are numerous records for that year and does not mean that all such events were actually registered.

  • Nassau County Clerk has Land Records from 1899, Court Records from 1899 and Naturalization Records. State court naturalization records remain in custody of the county clerks. Older court naturalization records have been transferred to the National Archives--Northeast Region. The County Clerk is the keeper of most civil and criminal trial court records for Supreme Court and County Court, naturalizations, marriages (1908–35), censuses (Some county clerks' offices hold duplicate copies of some of the State censuses taken periodically between 1825 and 1925 and copies of the federal census), as well as deeds and mortgages.
  • Nassau County Surrogate Court Clerk has Probate Records from 1899. The County Surrogate Court Clerk maintain records of wills, letters testamentary, letters of administration, orders and decrees, and appointments of guardians; and filed papers, including original wills, petitions for probate (gives date of death and lists next of kin), performance bonds, property inventories (seldom found after ca. 1900), administrator's or executor's accountings, etc. Surrogate's Courts create comprehensive indexes to records and files.
  • Nassau County Treasurer is responsible for the collection of taxes.
  • Nassau County Historian maintains archival holdings for virtually every facet of the county’s history. In New York State, every municipality (town, city, village, county) must have an appointed historian. Most of the towns have their own historians as well and each can be contacted. The County Historian may provide access to obituaries, vital records, church records, maps, and family files or journals. Some historians provide search services for their office records and others may refer you to local genealogists who research in the area.

Nassau County, New York Census Records

  • Learn More: State of New York Census Records
  • U.S. Federal Population Schedules: 1900, 1910, 1920, 1930, 1940
  • U.S. Census Reconstructed Records: None
  • State Population Schedules: 1905, 1915, 1925
  • Other State Census Schedules: None
  • U.S. Federal Census Mortality Schedules: None
  • Selected U.S. Federal Census Agriculture Schedules: None
  • Selected U.S. Federal Census Industry Schedules: None
  • Union Veterans Schedules: None

Nassau County, New York Vital Records

Nassau County, New York Resources

Nassau County, New York External Links