O
OAT (see Onward Air Transmission.)
Obama, Barack H. 1961-. President of the United States, 2009-
Obchodní Psaní [Obchodni Psani]
- Bush, Joseph Edward. 1911-2001
- Fischmeister, Ladislav V. 1923-2003
- Freer, Phillips B. 1910-2009
- Grau, Juan Santaeugenia. 1919-2000
- Herčik, Josef. 1922-1999 [Hercik, Josef]
- Hutyra, František. 1930-1998 [Hutyra, Frantisek]
- Janečka, Joseph J. 1913-1991 [Janecka, Joseph J]
- Ježek, Jaroslav. 1908-1991 [Jezek, Jaroslav]
- Jolly, Michael D.. 1940-1997
- Konštant, Václav [Konstant, Vaclav]
- Kopřiva, Thomas [Kopriva, Thomas]
- Kovářík, Vladimír. 1921-1999 [Kovarik, Vladimir]
- Krejčí, Otakar M. 1915-1997 [Krejci, Otakar M]
- Kvašnička, Zdeněk. 1905-1993 [Kvasnicka, Zdenek]
- Linhart, Edward C. 1913-2004
- Markus, Vladimír [Markus, Vladimir]
- Molíš, Zdeněk [Molis, Zdenek]
- Mrňák, Jan [Mrnak, Jan]
- Ondrášek, Hynek [Ondrasek, Hynek]
- Palaschak, Leonard J. 1930-1993
- Palkoska, Vratislav. 1923-2001
- Ruzicka, Karel Josef. 1928-2007
- Strechansky, Anthony. 1933-1999
- Tachecí, Antonín. 1926-2003 [Tacheci, Antonin]
- Tekeľ, Joseph [Tekel, Joseph]
- Vaník, Václav [Vanik, Vaclav]
Observatories (see Andrejov Observatory.)
Obtisk (see Offsets.)
Occupation Stamps (see Provisional and Revolutionary Overprints, 1945 - U.S. Army Overprint.)
Officers (see Society for Czechoslovak Philately - Membership.)
Official Mail (see also Bohemia and Moravia - Official Mail.)
Okresní Cancels [Okresni Cancels] (see Cancels - By Type - District.)
Olbracht, Ivan. 1882-1952 (see Writers - Olbracht, Ivan. 1882-1952.)
Old-New Synagogue (see Alt Neu Shul.)
Old Bohemia Mission. Warwick, MD
Olomouc Liberation Issue, 1945
- 1984. 90th Anniversary Issue
- 1994. 100th Anniversary Issue
Olympic Committee. Czechoslovak
- 1966. 70th Anniversary Issue
- 1971. 75th Anniversary Issue
- 1999. 100th Anniversary Issue
- 1996. Atlanta Summer Olympics Surcharge
Olympic Congress Issue, 1925
Cancels (see Cancels - By Event - Olympic Congress.)
Olympic Games (see also American Army Olympic Games. 1945.)
- 1965. Czechoslovak Victories Issue
- - - Counterfeits and Forgeries
- 1996. 100th Anniversary of the Modern Games
Ancient (see also Ancient Olympic Games Issue.)
- 1996. 100th Anniversary of the Modern Games
- - Withdrawn Stamps (see also Sports Issue - 1984.)
Olympic Games. Summer [Czech] (see also Paralympic Games. Summer [Czech].)
Olympic Games. Summer [Slovak] (see also Paralympic Games. Summer [Slovak].)
Olympic Games. Winter [Czech] (see also Paralympic Games. Winter [Czech].)
Olympic Games. Winter [Slovak]
Ondrášek, Hynek [Ondrasek, Hynek]
Ondříček, František. 1857-1992 [Ondricek, Frantisek] (see Musicians - Ondříček, František. 1857-1992.)
- - 1964. 150th Anniversary Issue
- 1989. 50th Death Anniversary
Orbis (see Filatelie Orbis.)
- Bratislava Radio Symphony Orchestra
- - 1986. 90th Anniversary Issue
- - 1996. 100th Anniversary Issue
- Czechoslovak Radio Symphony Orchestra
- - 1976. 50th Anniversary Issue
- - 1974. 25th Anniversary Issue
- - 1999. 50th Anniversary Issue
Organization for Security and Cooperation in Europe
- 2000. 25th Anniversary Issue
Orlík [Orlik]
Orlík Castle [Orlik Castle]
Ossuaries (see Charnel Houses.)
- - Counterfeits and Forgeries
- 2001. European Men's Volleyball Championship Issue
Dvořák Theater [Dvorak Theater] (see Dvořák Theater.)
Ostrčil, Otakar. 1879-1935 [Ostrcil, Otakar] (see Musicians - Ostrčil, Otakar. 1879-1935.)
Osvobezená Republika [Osvobezena Republika] (see Chainbreaker Issue.)
Overprints (see also Surcharges.)
[Here are listed general articles about overprints and the names of specific operprints]
Aleš Valenta Zlatá Medaile [Ales Valenta Zlata Medaile] (see Sports - Skiing - Winter Olympic Games Issue - Overprinted.)
Biplane Image and Surcharge (see Air Mail - 1920.)
Brussels Philatelic Exhibition. 1945 (see Brussels Philatelic Exhibition. 1945 - Overprinted Exhibition Souvenir Sheets.)
Canadian National Exhibition, Toronto. 1939 (see Canadian National Exhibition, Toronto. 1939 - Overprinted Exhibition Souvenir Sheets.)
Carpatho-Ukraine (in Cyrillic Lettering) (see Chust Overprint.)
Congres Olymp Internat. Praha 1925 (see Masaryk, Thomas Garrigue. 1850-1937. President of Czechoslovakia. 1918-1937 - 1925 - Overprints - Olympic Congress.)
Čechy a Morava [Cechy a Morava] (see Bohemia and Moravia - Czechoslovakia Overprinted.)
ČSR Zahraniční Pošta [CSR Zahranicni Posta] (see Field Post - France - 1944. ČSR Zahraniční Pošta.)
ČSSR Mistrem Světa [CSSR Mistrem Sveta] (see Sports - Hockey - 1962.)
Doplatit (see Postage Dues.)
Eastern Silesia (see Eastern Silesia.)
K. Neumannová/Zlatá Medaile (see Olympic Games. Winter [Czech] - 2006 - Overprint.)
Liberation (see Provisional and Revolutionary Overprints, 1945.)
Masaryk Semi-Postal Overprints (see Masaryk, Thomas Garrigue. 1850-1937. President of Czechoslovakia. 1918-1937 - 1925 - Overprints.)
New York World's Fair. 1939-1940 (see New York World's Fair. 1939-1940 - Overprinted Exhibition Souvenir Sheets.)
Noviny (see Newspaper Stamps - 1926. Noviny Overprint.)
Opening of Slovak Parliament (see Slovakia - Opening of Slovak Parliament.)
Pausalovana Potravi Dan with Surcharge (see Postage Dues - Food Service Tax Stamps.)
Pošta Československá 1919 [Posta Ceskoslovenska 1919] (see Pošta Československá 1919.)
Provisional and Revolutionary Overprints, 1918-1919 (see Provisional and Revolutionary Overprints, 1918-1919.)
Provisional and Revolutionary Overprints, 1945 (see Provisional and Revolutionary Overprints, 1945.)
Příjezed presidenta Masaryka [Prijezed presidenta Masaryka] (see Scout Mail - Overprints - Příjezed presidenta Masaryka.)
Red Cross Emblem with Surcharge (see Red Cross Issues - 1920.)
Slovenský Stát [Slovensky Stat] (see Slovakia - Slovenský Stát Overprints.)
SO 1920 (see Eastern Silesia.)
VII. Slet Všesokolský Praha 1926 (see Masaryk, Thomas Garrigue. 1850-1937. President of Czechoslovakia. 1918-1937 - 1925 - Overprints - Sokol.)
VZOREC (see Specimens.)
Wie Sind Frei (see Sudetenland - Provisional Stamps.)
Overun Nations Issue (see Czechoslovak Subjects on Foreign Stamps - United States - 1943. Overrun Nations.)
- 1986. Protection of Birds Issue
Oysters (see Animals - Oysters.)