Online (web) exhibitions are included in 'Web articles and commentaries on specific topics in the History of Cartography' and also in 'Images of early maps on the web'. In each case, the exhibitions are prefixed with +

For details of current and forthcoming exhibitions in the real world see John Docktor's listing. If you want historical information, follow links from the head of that page to the separate listings for exhibitions that closed in previous years. The Brussels Map Circle [BIMCC] (formerly Brussels International Map Collectors' Circle) maintains a register of International news and events (including a section on Exhibitions).

Also see the Smithsonian Institution's excellent 'Library and Archival Exhibitions on the Web'. "This site features links to online exhibitions that have been created by libraries, archives, and historical societies, as well as to museum online exhibitions with a significant focus on library and archival materials". You can search the featured exhibits (from 1995 onwards and mostly in the US) individually or, in 'Subject', by, e.g. 'maps' or 'exploration'. In October 2011, there were over 6,200 entries. Check regularly for 'Recent Additions'.

Also worth consulting is Matthew Edney's ’The history of map exhibitions’ (in his Mapping as Process blog, 27 November 2022)

For a look under the bonnet / hood, see the video of a talk on 28 September 2016: 'You are Here … at last: The story of the map exhibition', where Paula Williams talks about the challenges of selecting and mounting the National Library of Scotland’s exhibition You are Here: A journey through maps.