Adolf Passer FRPSL (c. 1864 – 14 August 1938) was an Austrian philatelist and authority on the stamps of Austria, Bosnia and Herzegovina and the Ottoman Empire and Turkey.

A stamp collector from a young age, Passer was able to exploit his professional connections in the shipping industry to expand his collection when he worked in London in the late 1880s.

He wrote a book on the stamps of Bosnia and Herzegovina and another on those of the Ottoman Empire and Turkey, published by the Royal Philatelic Society, London, in 1938 and regarded at the time as almost the last word on the subject.

[1] Passer travelled to London in 1885 where he worked in a shipping firm, his interest in philately being rekindled by the opportunities to collect stamps that arose from his employer's business.

[6] He organised the Vienna Philatelic Exhibition 1911, for which he was awarded the Goldene Verdienstkreuz mit der Krone (Gold Cross of Merit of the Crown) by Emperor Franz Joseph I.