Alois Fantl was born on 27 April 1873 in Wittingau, Bohemia (now Třeboň, Czech Republic), as the son of Karl and Therese Fantl. In 1902 he married Bertha, née Pokorny, and they had a daughter, Margarethe. His second marriage in 1921 to Sofie Szécsi, née Pollak, remained childless. After working for several years in bookshops, he founded his own bookshop on 1 September 1919 at Liechtensteinstraße 23 in Vienna's 9th district, with an antiques business and, from 25 April 1931, a lending library. Alois and Sofie Fantl were both of Jewish origin and subject to persecution after the annexation of Austria to the Nazi German Reich. From August 1938, Alois Fantl attempted to prevent the threatened liquidation of his business and hence the loss of all of his books. To allow him to sell them himself, he even transferred them to his private apartment and attempted to obtain an extension of the liquidation deadline from the Vermögensverkehrsstelle (VVSt) (Property Transaction Office) and the Reichsschrifttumskammer (Reich Literature Chamber) in Berlin. Although this was granted until 30 September 1938, an instruction was issued on 14 September 1938 by the VVSt to appoint Gottfried Linsmayer as provisional administrator. After the closure of his business at the end of September and the sealing of the shop on 10 October, Fantl was finally denied access to his inventory. Until then he had managed to sell around one-third of his stocks, including the most valuable part to booksellers for some 1,200 Reichsmarks and 2,500 volumes from his lending library for 350 Reichsmarks. The remaining stock was to be liquidated. According to the asset declaration made shortly before his deportation, they were worth only 26 Reichsmarks. The last address of the Fantl family was in the Sammelwohnung (collective apartment) at Stoß im Himmel 3/7 in the 1st district. Alois and Sofie Fantl were deported together to Theresienstadt ghetto on 29 July 1942 and from there on 15 May 1944 to Auschwitz, where they were murdered.

Five books (three accession numbers) have been discovered in the branch library for the history of medicine at the Medical University of Vienna, all with the ex libris Alois Fantl Buchhandlung und modernes Antiquariat Wien IX. Liechtensteinstraße 23. According to the handwritten comments in the books, they were acquired between February and March 1943 by the former Institute for the History of Medicine. All five books were offered for sale by an antiques shop at Dr.-Karl-Lueger-Platz 3 in the 1st district, which was Aryanized in 1938 by the bookseller Karl Stark (1886–1949) and was later heavily involved in the Nazi book looting. Heirs are currently being sought for restitution.