Nassau County Genealogy Search

Nassau County genealogy records begin in 1899 when the county was carved from the eastern part of Queens County. The county seat is Mineola, where the county clerk and surrogate's court are based. Because Nassau County is relatively young compared to other New York counties, many pre-1899 records are held by Queens County or at the state level. Still, the county has rich record collections that cover more than a century of Long Island family life. Knowing where the records split between Queens and Nassau is key to a good search.

Nassau County Clerk Genealogy Records

The Nassau County Clerk at 240 Old Country Road, Mineola, NY 11501 maintains land records from 1899 to the present. Court records from the same year include Supreme Court and County Court filings. The office also keeps marriage records from 1908 to 1935 and naturalization records. New York State Census records for 1915 and 1925 are available here. Phone (516) 571-2660 for details.

Before 1899, the land that is now Nassau County was part of Queens County. If your family was in this area before that split, you will need to check Queens County records or the state archives for earlier documents. Land deeds, court records, and vital records from before 1899 are not at the Nassau County Clerk. This is the single most important thing to know for Nassau County genealogy research.

The clerk's office has indexes for land records by grantor and grantee name. Court records are indexed by case parties. Staff can help you find the right index but they cannot conduct research for you. Copy fees apply.

Nassau County Genealogy Resources

The FamilySearch website offers free access to many New York genealogy collections, including records that cover Nassau County and its parent, Queens County.

You can search the FamilySearch catalog by county name to find digitized records, microfilm holdings, and indexed collections for Nassau and surrounding Long Island counties.

Vital Records in Nassau County

Vital records in Nassau County follow the standard New York State rules. Town clerks within the county hold birth and death records for events that took place in their towns. The NYS Department of Health has statewide vital records indexes from around 1880 to 1881, though Nassau County itself did not exist until 1899.

Under Public Health Law Sections 4173 and 4174, genealogy copies of birth records are available after 75 years if the person is known to be dead. Death records open after 50 years. Marriage records need 50 years and proof that both spouses have died. The state charges $22 for a three-year search, with higher fees for wider date ranges. Processing can take eight months or more. Contacting the local town clerk where the event took place is usually faster.

For pre-1899 vital events in what is now Nassau County, records may be at the old Queens County offices or the state level. This is because the towns of Hempstead, North Hempstead, and Oyster Bay were part of Queens before the split.

Nassau County Probate Records

The Nassau County Surrogate's Court at 262 Old Country Road, Mineola, NY 11501 keeps probate records from 1899 to the present. Files include wills, letters testamentary, administration papers, and estate inventories. Call (516) 571-2510 for fee information.

Under the Surrogate's Court Procedure Act, each county surrogate's court handles wills and estate settlements. To request records, send a written letter by mail with the name of the deceased and the date of death. The court does not take email requests. For probate matters before 1899, check the Queens County Surrogate's Court since Nassau was part of Queens at that time. Colonial-era wills from the 1600s and 1700s are at the New York State Archives and many have been digitized on Ancestry.com for free use by New York residents.

Nassau County Historian and Archives

The Nassau County Historian in Mineola keeps family files, cemetery records, and local history materials. The historian's office can point you toward the right sources for your Nassau County genealogy research. They maintain vertical files sorted by surname and by subject. Basic help is free, though copy fees may apply.

The New York State Archives in Albany holds more than 200 million documents. Military records, naturalization abstracts, and state census originals can all cover Nassau County residents. Under Arts and Cultural Affairs Law Section 57.05, the archives collects and preserves official records from every county. You can visit in person without an appointment. Bring a photo ID.

The New York State Census was done in 1915 and 1925 for Nassau County. Earlier census years from 1825 through 1905 would be under Queens County records since Nassau did not yet exist. These census records fill in gaps between federal census years and can list birthplace, occupation, and household details useful for genealogy.

Land Records for Nassau County Genealogy

Land records at the Nassau County Clerk start in 1899. Deeds, mortgages, and liens are indexed by grantor and grantee. For land transactions before 1899 in Hempstead, North Hempstead, or Oyster Bay, you will need to check Queens County land records or the state-level collections at the NYS Archives.

Land records are a good secondary source for genealogy. They often name family members, neighbors, and witnesses. Under the Estates, Powers and Trust Law, property that passes at death must follow specific rules. Estate-related deeds can confirm family ties when vital records have gaps. Copy fees at the clerk's office are modest.

Cities in Nassau County

These towns in Nassau County have their own genealogy resource pages with local details.

Nearby Counties

Counties near Nassau County with their own genealogy record collections.