Mike Collins emails a weekly "Letter from Ireland," which is free. When people sign up for the letter, they're asked to share the Irish surnames in their family tree.

Based on the large database Collins has built over the last four years, these are the top ten most numerous Irish surnames, in reverse order: 

10. Collins

9. Murray

8. O'Connor

7. O'Brien

6. Ryan

5. McCarthy

4. Walsh (also Walshe/Welsh)

3. Sullivan

2. Kelly

1. Murphy

This week's letter summarizes the origins of these names and where they are most commonly located.

Sign up to receive "A Letter from Ireland" every Sunday morning:  https://youririshheritage.com/letterfromireland/.