Terrence O’Loughlin Carlo Giuseppe Oddone Giuseppe Odoardi Freeman Adams Oliver J. Olry August Olshovy James Omond Imre Orban Archimede Orlandini Giuseppe Ornati Enrico Orselli George A. Ostertag Anton Ostler Louis Otto Ludwig Otto Jean Ouvrard John William Owen J. D. O’brien Vincent O’brien Roger Francis O’Donnell J. O’Laughlin James O’Mahoney W. W. Oakes Marcus (I) Obbo Marcus (II) Obbo Vladimir Oberberg Carl Oberg Englbert Oberhoffer Johann Carl Oberkirsch Rudolf Oberlander Alexander Obermaier Bartolomeo (I) Obici Bartolomeo (II) Obici Prospero Obici Marquis Tomasso Degli Obizzi Mathias Obrecht Henry P. Ochs William Octigan Giuseppe Morello Odani Gunder Odden

Antonio (I) Odoardi Hubert Jan Odoj Gustaf Odulf Johann Valentin Oelling Heinrich Christian Oerlecke N. Oernberg Louis Oertel Arthur Oettel A. J. Oettinger Abraham Jooseten Van Offenbeeck Johann (I) Ohberg Johann (II) Ohberg Heinrich Ohlhaver Emil Ohlsson Emil E. Ohlsson John Ohlsson Friedrich Wilhelm Ohm John Ohman Oliver G. Olafson Thomas Oldham Albrecht Olert Carl E. Oliver James Oliver John W. Oliver Nelson Oliver Samuel N. Oliver Walter L. Oliver Felice Oliveri Vincenzo Oliveri Christian Olivier Francesco Olivola S. C. Olmstead Axel Olofsen A. J. Olofsen Diederich Olrichs Anton Gustav Olsen Cheston S. Olsen Coleman F. Olsen Engel Olsen Franz Josef Olsen

Harold Justin Olsen Lars Jorgen Rudolph Olsen O. H. Olsen Anton Olson Edvin Olsson J. E. Olsson Karl Harry Olsson George E. Olstead Albert Olsterman Ignazio Ongaro Zuanne Ongaro Nicolaus Onizin Karl Onken Alex Oosten Walter Opel Johann Georg Opfermann A. J. Opie G. K. Oppedal Pieter Opperdoes Ivar Orestad Ernesto Orlandi Orlando Orlandi Heinrich Christian Orlecke Daniel Orloff George P. Orr Giuseppe Orselli Giacomo Orselli Giovanni Orsi Ercole Orsini Gianni Orsini Olao Orsoni Ascencio Ortega Mariano Ortega Silverio Ortega George O. Orth Louis Orth Joseph Orto Phillip Orton Ory Tommasso Orzero

C. E. Osborne Henry Osborne Samuel Osborne Michael P. Osgar William Frederick Oskay William Osmond Knut Ostensson Reinhold Ostergren Hugo Osterholdt Andreas Ostermunchner Andreas Ostler Frantz Ostler Carl Thomas Ostrander Eugene Ostrander Anton Ostrizek Joseph Ostroy Karl August Otho Andreas Ott Johann Ott Joseph Ott Martino Ott Jacob Ottley Bernhard August Otto Carl August Otto Carl Christian Otto Carl Wilhelm Friedrich Otto Ernst Albin Otto Ernst Louis Georg Otto Georg August Gottfried Otto Gustav Otto Gustav Karl Otto Heinrich Ferdinand Otto Heinrich Wilhelm Otto Herbert Barthold Otto Hermann Otto Jacob August Otto Johann Karl August Otto Kurt Otto Oskar Robert Otto Otto Otto

Paul Max Otto Rudi Otto Theodor Otto Ulrich Otto Wilhelm Otto Ottomanus Bernard Ouchard Emile Auguste Ouchard Emile Francois Ouchard Jean Claude Ouchard Frederick Outram L. E. Overpeck Ivy Rimmer Owen Anton Johan Owesen Lief Asbjorn Owesen Joseph Oxley S A Oeberg Adam Gottfried Oehme A Opikhtin di Giovanni Filippo Orazio Josef Orelli d’Essentier Orinthio Friederich Ortlieb E P van Osch Carl Gustav Otto Gio Battista Oneda