Oberschlesien / Upper Silesia (2)

Objektkunst / object Art (16)

Obstanbau / fruit-growing (1)

Obstbau / pomiculture (1)

Obstzucht / fruit farm (4)

Okkultismus / occultism (3)

Ökologie / ecology (1)

Ökonomie / economy (66)

Ölbild / oil paint (12)

Olympiade / Olympiad (1)

Olympische Spiele / Olympic Games (1)

Ontologie / ontology (1)

Op-Art / optische Kunst (3)

op-art, optical art / optische Kunst (3)

Oper / opera (11)

Operette / operetta (1)

Operngeschichte / history of opera (10)

Optik / optics (9)

Orchester / orchestra (2)

Orchideen / orchids (1)

Orden / Medal / decoration (4)

Orden / order, religious order (40)

Ordenstracht / habit of a religious order (40)

Organische Chemie / organic chemistry (1)

Orgel / pipe organ (1)

Orgelbau / organbuilding (1)

Orgelgeschichte (1)

Orient / orient (33)

Orientalistik / orientalism (5)

Orientteppich / oriental carpet, eastern carpet (1)

Original Acrylstich / original acryl engraving (1)

Original Aquarell / original watercolour painting (10)

Original Ölbild / original oil painting (11)

Original-Fotografie / Original-Photographie / original photograph (68)

Original-Grafik / Original-Graphik / original graphic (546)

Original-Heliografie / original-heliographic print (1)

Original-Heliogravüre / original-heliogravure (2)

Original-Holzschnitt / original woodcut (171)

Original-Holzstich / original wood engraving (21)

Original-Kupferstich / original copper engraving (56)

Original-Linolschnitt / original linocut (49)

Original-Lithografie / Original-Lithographie / original lithograph (211)

Original-Offset / original offset (8)

Original-Plastik / original sculpture (7)

Original-Radierung / original etching (392)

Original-Siebdruck, Serigrafie / original screenprint, silkscreen, serigraphy (37)

Original-Siebdruck, Serigrafie / original screenprint, silksreen, serigraphy (48)

Original-Zeichnung / original drawing (52)

Original-Zinkografie / original zincograph (3)

Originalfotografie / Originalphotographie / original photograph (2)

Originalgrafik / Originalgraphik / original graphic (48)

Originalholzschnitt / original woodcut (2)

Originalkupferstich / original copper engraving (9)

Originallinolschnitt / original linocut (3)

Originallithografie / Originallithographie / original lithograph (1)

Ornament, Ornamentik / fancywork / ornament (8)

Ornithologie, Vogelkunde / ornithology (8)

Ortskunde / Landeskunde / applied geography (192)

Osmanen / Ottomans (1)

Osmanisches Reich / Ottoman Empire (1)

ostasiatische Kunst / far eastern art (2)

Österreich / Austria (14)

österreichische Geschichte / austrian history (15)

österreichische Kunst / austrian art (14)

österreichische Literatur / austrian literature (31)

Osteuropa / eastern europe (8)

Ostpreußen / East Prussia (27)

Ostsee / Baltic sea (1)

Ozeanien / Oceania (3)