Pourquoi-Pas or Pourquoi Pas? (from French pourquoi pas? 'why not?') may refer to one of these ships:
- Four ships owned by the French navigator and naval officer Jean-Baptiste Charcot:
- Pourquoi-Pas (1893), a 19.5-metre (64 ft) cutter that Charcot had built in 1893 and in which he made a 2-week voyage in 1894. He sold her in 1896 to buy Pourquoi Pas ? II
- Pourquoi-Pas (1896), the new name given by Charcot to a 26-metre (85 ft) wooden schooner he bought in 1896, sold in 1897, and bought back in 1897; from 1897 he sailed her in British waters and in 1902 sailed towards Iceland, entering the Arctic Circle for the first time and approaching the glaciers
- Pourquoi-Pas (1897), the new name given by Charcot to a 31-metre (102 ft) iron schooner with a steam-engine he acquired in 1897 and in which he sailed down the River Nile as far as Aswan with the millionaire Vanderbilt
- Pourquoi-Pas (1908), the most famous of the four
- Pourquoi Pas? (2005), a research vessel of the IFREMER and the French Navy, named in honour of the previous ships