Last Names Beginning with O: A Comprehensive Guide

Looking for a unique and meaningful last name that starts with the letter "O"? This comprehensive list explores a variety of origins and meanings for last names beginning with O, offering diverse options for individuals seeking a distinctive family name.
1. **O'Brien:** Meaning "descendant of Brian," a popular Gaelic name often associated with Irish heritage.

2. **O'Connor:** Meaning "descendant of Connor," another popular Gaelic name, this surname is also deeply rooted in Irish ancestry.

3. **O'Donnell:** Meaning "descendant of Donnell," a common Irish name often associated with nobility and leadership.

4. **O'Neill:** Meaning "descendant of Niall," a powerful Gaelic name symbolizing strength and leadership.

5. **Oliver:** Derived from the Latin word "oliva," meaning "olive tree," Oliver symbolizes peace and prosperity.

6. **Olson:** Meaning "son of Ole," a Scandinavian name, this surname reflects a strong connection to Norwegian heritage.

7. **Olsen:** Meaning "son of Ole," this surname is also of Scandinavian origin, specifically Danish and Norwegian.

8. **O'Malley:** Meaning "descendant of Maol-mhuire," meaning "devotee of Mary," this surname is of Irish origin.

9. **O'Mara:** Meaning "descendant of Máire," meaning "Mary," this surname is of Irish origin.

10. **O'Reilly:** Meaning "descendant of Raghallach," meaning "vigorous" or "brave," this surname is of Irish origin.

11. **O'Rourke:** Meaning "descendant of Ruairc," meaning "red king," this surname is of Irish origin and often associated with nobility.

12. **Owen:** Meaning "noble" or "well-born," this name is of Welsh origin and has a strong, dignified connotation.

13. **Ortega:** Meaning "bear," this surname is of Spanish origin and is often associated with strength and courage.

14. **Ortiz:** Meaning "golden," this surname is of Spanish origin and is often associated with wealth and prosperity.

15. **Osborne:** Meaning "divine spear," this surname is of English origin and has a strong and powerful connotation.

16. **Oscar:** Meaning "divine spear," this name is of Norse origin and has a strong and heroic connotation.

17. **Otis:** Meaning "wealthy," this surname is of English origin and has a prosperous connotation.

18. **Otto:** Meaning "wealthy" or "prosperous," this name is of German origin and has a strong and successful connotation.

19. **O'Toole:** Meaning "descendant of Ó Tuathail," meaning "descendant of Tuathal," this surname is of Irish origin.

20. **Overton:** Meaning "over the town," this surname is of English origin and is often associated with a location.

21. **O'Brien:** Meaning "descendant of Brian," a popular Gaelic name often associated with Irish heritage.

22. **O'Connell:** Meaning "descendant of Conchobhair," meaning "wolf," this surname is of Irish origin and has a strong and powerful connotation.

23. **O'Connor:** Meaning "descendant of Connor," another popular Gaelic name, this surname is also deeply rooted in Irish ancestry.

24. **O'Grady:** Meaning "descendant of Gráda," meaning "love," this surname is of Irish origin and has a romantic connotation.

25. **O'Hara:** Meaning "descendant of Ó hAodha," meaning "descendant of Aodh," this surname is of Irish origin.

26. **O'Keefe:** Meaning "descendant of Ó Caoimh," meaning "gentle," this surname is of Irish origin and has a kind and gentle connotation.

27. **O'Laughlin:** Meaning "descendant of Lochlainn," meaning "from the lake of Loughlann," this surname is of Irish origin.

28. **O'Leary:** Meaning "descendant of Ó Laoiri," meaning "descendant of Laoire," this surname is of Irish origin.

29. **O'Malley:** Meaning "descendant of Maol-mhuire," meaning "devotee of Mary," this surname is of Irish origin.

30. **O'Mara:** Meaning "descendant of Máire," meaning "Mary," this surname is of Irish origin.

31. **O'Neil:** Meaning "descendant of Niall," a powerful Gaelic name symbolizing strength and leadership.

32. **O'Reilly:** Meaning "descendant of Raghallach," meaning "vigorous" or "brave," this surname is of Irish origin.

33. **O'Rourke:** Meaning "descendant of Ruairc," meaning "red king," this surname is of Irish origin and often associated with nobility.

34. **O'Shaughnessy:** Meaning "descendant of Ó Séaghdha," meaning "descendant of Séaghdha," this surname is of Irish origin.

35. **O'Sullivan:** Meaning "descendant of Ó Súilleabháin," meaning "descendant of Súilleabháin," this surname is of Irish origin.

36. **O'Toole:** Meaning "descendant of Ó Tuathail," meaning "descendant of Tuathal," this surname is of Irish origin.

37. **Odell:** Meaning "from the hill," this surname is of English origin and is often associated with a location.

38. **Ogden:** Meaning "at the oak tree," this surname is of English origin and is often associated with a location.

39. **Oliver:** Derived from the Latin word "oliva," meaning "olive tree," Oliver symbolizes peace and prosperity.

40. **Olmsted:** Meaning "from the elm tree," this surname is of English origin and is often associated with a location.

41. **Olsen:** Meaning "son of Ole," this surname is also of Scandinavian origin, specifically Danish and Norwegian.

42. **Olson:** Meaning "son of Ole," a Scandinavian name, this surname reflects a strong connection to Norwegian heritage.

43. **O'Malley:** Meaning "descendant of Maol-mhuire," meaning "devotee of Mary," this surname is of Irish origin.