How to Find French Cousins with DNA

Finding a living cousin in France is one of the great rewards of genetic genealogy. A cousin may hold family photographs, know the village, and share stories your family never told. It is also harder than it sounds, because genealogical DNA testing is illegal in France and the pool of French matches is thinner than in other countries. This guide gives a practical plan for finding and contacting French cousins, and for doing it respectfully.

Set realistic expectations

French testers are fewer than in other countries, because the law has kept them away from the mainstream market. Estimates put the number of French people who order kits from abroad at roughly 100,000 to 200,000 a year, depending on the source, so they exist, but you will not see them on every match list. Many of your French cousins may be people of French descent living elsewhere, in the United States, Canada, or other countries. A match with a French surname and a tree rooted in your ancestor’s commune is a great find whether the cousin lives in Lyon or in Louisiana.

Step 1: Test where the French matches are

• MyHeritage is strong in continental Europe and is where many French testers appear. Upload data from other companies for free to reach its pool. See our review.
• AncestryDNA is the largest database and has many descendants of French emigrants in North America, but it does not ship to France.
• FamilyTreeDNA and GEDmatch add further pools, and accept uploads.

Remember that Geneanet closed its DNA section in December 2023, so it is not a source of DNA matches. For where each test is sold, see The DNA Geek’s guide to where each test is sold.

Step 2: Build your tree first

Matches mean little without a tree. Build your tree back to the immigrant and, if possible, to a French commune, using our starter kit and our guide to finding the commune of origin. A tree with French place names lets other people recognize the connection.

Step 3: Work your match list

1. Sort by shared DNA and the longest segment. Closer relatives share more DNA, and a long single segment is a better sign of a recent relationship than many small ones.
2. Scan trees for French surnames and places that match yours. Our surname guide will help with variants.
3. Use shared matches and clustering tools to group matches by family line.
4. Look at the chromosome browser where available, to see where you share DNA.
5. Keep a spreadsheet of matches, the amount of DNA, the line you suspect, and whether you have made contact.

Step 4: Contact matches with care

A short, friendly, specific message gets the best replies. Mention the surname or commune you think you share, the amount of DNA, and one clear question. A French-language greeting is a courteous touch, even if the rest is in English.

This is an invented example for illustration. Adapt it to your own facts.

Be sensitive to the legal context

A French match may be cautious about discussing a test, because testing is illegal in France. Do not press for details of how or where they tested, and do not share their messages publicly. Keep the conversation on the family history, and respect any wish for privacy. Our guide to DNA testing law in France explains the background.

Step 5: Confirm with records

A DNA match is a clue, not proof. Take the suspected common ancestor and check the civil and parish registers. Our guide to connecting DNA matches to French records shows how, and our archives guide shows where to look.

What if no French cousins appear?

• Widen the net. Check matches whose trees include any part of your ancestor’s département, not only the commune.
• Look at descendants of the family elsewhere. Siblings of your ancestor may have emigrated to other countries.
• Add another company. Uploads are free at several sites.
• Rely on the records. French records are so good that DNA is a bonus, not a necessity.
• Be patient. Databases grow, and new matches appear over time.

Illustrative composite (not a real family): A man in Michigan finds a match who lists a village near Besançon in her tree. They share about 90 cM. After a polite exchange, she sends a photograph of a family grave. The man checks the civil registers and finds the two lines meet at a marriage in 1868.

For the overall comparison of tests, see our best DNA test for French ancestry. For the full method, see our complete guide to tracing French ancestry.

Where French cousins hide: the emigrant branches

The most likely “French” cousins on your list may not live in France at all. The siblings of your emigrant ancestor, and their children, may have settled in Quebec, Louisiana, New England, South America, or elsewhere, and their descendants are testing in far larger numbers than French residents. Check the trees of matches whose ancestors share your surname and region, wherever the match lives today. Our history of French emigration to America shows where branches of French families went.

A realistic first-year plan

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