| Carlos Ocadiz (Aguascalientes, MX) | Edmond O'Callaghan (Kilworth, IE) | Kevin Jude O'Callaghan (Algonquin, IL) |
| Timothy D. Ocain (Framingham, MA) | Fergus G. O'Callaghan (Eindhoven, NL) | Liadan O'Callaghan (Mountain View, CA) |
| Timothy D. Ocain (Waltham, MA) | James O'Callaghan (New York, NY) | Michael O'Callaghan (Weston-Super-Mare, GB) |
| Timothy D. Ocain (Princeton, NJ) | James Joseph O'Callaghan (Dundalk, IE) | Michael G. O'Callaghan (Erie, PA) |
| Refik Ocakoglu (Brussels, BE) | James L. O'Callaghan (Salt Lake City, UT) | Michael J. O'Callaghan (Louisville, CO) |
| Murat Ocalan (Houston, TX) | Jeremiah J. O'Callaghan (Enfield, CT) | Nicholas O'Callaghan (Browns Plains, AU) |
| Ogan Ocali (Sunnyvale, CA) | John O'Callaghan (Skokie, IL) | Patrick J. O'Callaghan (Rockford, IL) |
| Ogan Ocali (Santa Clara, CA) | John O'Callaghan (Kemsing, GB) | Pauric O'Callaghan (Killybegs, IE) |
| Ogan Ocali (Baltimore, MD) | John O'Callaghan (Buchanan County, MO) | Richard J. O'Callaghan (Slidell, LA) |
| Aindrais O'Callaghan (Fort Lauderdale, FL) | John O'Callaghan (Willmette, IL) | Sorcha O'Callaghan (Dublin, IE) |
| Andrais O'Callaghan (San Francisco, CA) | John Mark O'Callaghan (Kent, GB) | Sorcha O'Callaghan (Lucan, IE) |
| Christopher A. O'Callaghan (Pasadena, CA) | John S. O'Callaghan (Skokie, IL) | Wendy O'Callaghan (Aurora, CA) |
| Daniel O'Callaghan (Limerick, IE) | John S. O'Callaghan (Wilmette, IL) | Wilfrid B. O'Callaghan (Kingston, CA) |
| Daniel O'Callaghan (Fairfax Station, VA) | John S. O'Callaghan (Willmette, IL) | Juan Manuel O'Callaghan Castella (Barcelona, ES) |
| Daniel J. O'Callaghan (Reston, VA) | Joseph O'Callaghan (Glounthaune, IE) | Michael P. O'Callaghan, deceased (late of Staten Island, NY) |
| Dennis J. O'Callaghan (Shreveport, LA) | Kevin J. O'Callaghan (Waterloo, CA) | Cynthia M. Ocamb (St. Paul, MN) |
| Donal J. O'Callaghan (County Cork, IE) | Kevin Jude O'Callaghan (Kingsport, TN) | |
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