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Guide to Miami County, Ohio ancestry, genealogy and family history, birth records, marriage records, death records, census records, family history, and military records.

County Facts
County seat: Troy
Organized: March 1, 1807[1]
Parent County(s): Montgomery[2]
Neighboring Counties
Shelby  • Darke  • Montgomery  • Clark  • Champaign
See County Maps
Miami County Ohio Courthouse.jpg
Location Map
OH miami.png

County Information


The county was named for the Miami Indians. It is located in the West-Central area of the state.[3]

County Courthouse

Miami County Courthouse
215 W Main St
Troy, OH 45373-3263
Phone: 937-440-3910
Miami County Website

Miami County, Ohio Record Dates

Information for this chart was taken from various sources, often containing conflicting dates. This information should be taken as a guide and should be verified by contacting the county and/or the state government agency.

Known Beginning Dates for Major County Records[4]
Birth* Marriage Death* Court Land Probate Census
1853 1807 1867 1807 1807 1807 1820
Statewide registration for births and deaths started in 1908. General compliance year is unknown.

Record Loss

There is no known history of courthouse disasters in this county.

Boundary Changes

Populated Places

For a complete list of populated places, including small neighborhoods and suburbs, visit Hometown Locator. The following are the most historically and genealogically relevant populated places in this county: [7]

Unincorporated communities

History Timeline


Bible Records

For an extensive list of resources for Bible Records see Ohio Bible Records.


Business, Commerce, and Occupations


Cemeteries of Miami County, Ohio online and in print
Tombstone Transcriptions Online
Tombstone Transcriptions in Print (Often more complete)
List of Cemeteries in the County
See Ohio Cemeteries for more information.


Census Records

Historical populations
Census Pop.
1810 3,941
1820 8,851 124.6%
1830 12,807 44.7%
1840 19,688 53.7%
1850 24,999 27.0%
1860 29,959 19.8%
1870 32,740 9.3%
1880 36,158 10.4%
1890 39,754 9.9%
1900 43,105 8.4%
1910 45,047 4.5%
1920 48,428 7.5%
1930 51,301 5.9%
1940 52,632 2.6%
1950 61,309 16.5%
1960 72,901 18.9%
1970 84,342 15.7%
1980 90,381 7.2%
1990 93,182 3.1%
2000 98,868 6.1%
2010 102,506 3.7%
Source: "".

Church Records

Church records and the information they provide vary significantly depending on the denomination and the record keeper. They may contain information about members of the congregation, such as age, date of baptism, christening, or birth; marriage information and maiden names; and death date. For general information about Ohio denominations, see Ohio Church Records.


  • Records of St. John's Lutheran Church, Piqua, in Evangelical Lutheran Church in America database at ($).

Court Records


Emigration and Immigration

Ethnic, Political, and Religious Groups

Funeral Homes


Miami Valley Genealogy Index at Preble County District Library is an Index to more than a half million pointers to records all over Miami Valley not just Miami County, Ohio.


Land and Property Records

Land and property records can place an ancestor in a particular location, provide economic information, and reveal family relationships. Land records include: deeds, abstracts and indexes, mortgages, leases, grants and land patents.

See Ohio Land and Property for additional information about early Ohio land grants. After land was transferred to private ownership, subsequent transactions were usually recorded at the county courthouse and where records are currently housed.

Local Histories

Local histories are available for this county. County histories may include biographies, church, school and government history, and military information. For more information about local histories, see Ohio Local Histories.

Maps and Gazetteers

Darke CountyShelby CountyChampaign CountyClark CountyMontgomery CountyOH MIAMI.PNG
Click a neighboring county
for more resources


Military Records

Civil War, 1861-1865
Civil War service men from Miami County served in various regiments. Men often joined a company (within a regiment) that originated in their county. Listed below are companies that were specifically formed in Miami County.

- 1st Regiment, Ohio Cavalry, Company I

World War I

Naturalization and Citizenship

Online Naturalization Indexes and Records


Miami County newspapers often contain genealogical value including obituaries, births, marriages, deaths, anniversaries, family gatherings, family travel, achievements, business notices, engagement information, and probate court proceedings.

For more Ohio newspaper information see Ohio Newspapers and Obituaries.


Other Records


Probate Records

From 1797 or the creation of the county, probate records were held by the Court of Common Pleas. After 1852, records are held by the Miami County Probate Court. Records include wills, estates, guardianships, naturalizations, marriage, adoption, and birth and death records (1867-1908 only). The records may give the decedent's date of death, name of spouse, children, parents, siblings, in-laws, neighbors, associates, relatives, and their place of residence.

See Ohio Probate Records for information about how to use probate records.

Online Probate Indexes and Records

School Records

Social Security Records

Tax Records

Ohio tax records complement land records and can be used in place of censuses before 1820 or to supplement the years between censuses. Because only persons who owned taxable property were listed, many residents were not included in tax lists. There may also be gaps of several years in the tax records of some counties.

Online Tax Indexes and Records

Vital Records

Vital records consist of birth, death, marriage and divorce records. Marriages were usually recorded from the formation of the county and are held at the office of the County Probate Court. Divorce records are located with the county Clerk of Courts.

Any existing birth and death records from 1867 through December 19, 1908 are located at the County Probate Court. The Ohio Department of Health has birth records filed after December 20, 1908 and death records filed after January 1, 1954, while the Ohio History Connection houses death records from December 20, 1908 through December 31, 1953.





Research Facilities


Listed below are archives in Miami County. For state-wide archival repositories, see Ohio Archives and Libraries.

Family History Centers

Family History Center and Affiliate Library Locator map - search for local Family History Centers or Affiliate Libraries

  • Family History Centers provide one-on-one assistance, free access to center-only databases, and to premium genealogical websites.
  • FamilySearch Affiliate Libraries have access to most center-only databases, but may not always have full services normally provided by a family history center.

Local Centers and Affiliate Libraries


Listed below are libraries in Miami County. For state-wide library facilities, see Ohio Archives and Libraries.

The following public libraries in Miami County have collections of particular interest to genealogists.

Troy-Miami County Public Library
419 W Main St
Troy, OH 45373

J. R. Clarke Public Library
102 E Spring St
Covington, OH 45318-1500

Milton-Union Public Library
560 S Main St
West Milton, OH 45383-1406

Piqua Public Library
116 W High St
Piqua, OH 45356

Tipp City Public Library
11 E Main St
Tipp City, OH 45371


Museum of Troy History
124 E Water St
Troy, OH 45373

The Miami Valley Military History Museum
Building 120
120 Ohio Ave
Dayton, OH 45428


Listed below are societies in Miami County. For state-wide genealogical societies, see Ohio Societies.

Miami County Historical & Genealogical Society, Inc
PO Box 808
Piqua, OH 45356

Troy Historical Society
PO Box 401
100 W Main St
Troy, OH 45373


Research Guides


  1. Ohio Atlas of Historical County Boundaries Ohio: Individual County Chronologies; Copyright The Newberry Library 2007
  2. Handybook for Genealogists: United States of America, 10th ed. (Draper, Utah: Everton Pub., 2002), Ohio.At various libraries (WorldCat); FHL Book 973 D27e 2002.
  3. Genealogy Trails History Group, “Miami County, Ohio Genealogy and History”, accessed 2/22/2017.
  4. Handybook for Genealogists: United States of America, 10th ed. (Draper, Utah: Everton Pub., 2002), Ohio.At various libraries (WorldCat); FHL Book 973 D27e 2002.
  5. Handybook for Genealogists: United States of America, 10th ed. (Draper, Utah: Everton Pub., 2002), Ohio.At various libraries (WorldCat); FHL Book 973 D27e 2002.
  6. Ohio Atlas of Historical County Boundaries Ohio: Individual County Chronologies; Copyright The Newberry Library 2007
  7. Wikipedia contributors, "Miami County, Ohio," in Wikipedia: the Free Encyclopedia,,_Ohio, accessed 3 January 2019.