Canada
Historical Canadian Newspapers Online: Links to historical Canadian newspapers that are freely available on the Internet
Ireland
Galway Advertiser Archive: All issues of the Galway Advertiser from 1970 to date are available to search and browse
Kildare Archaeological Society Journal 1891-2006 and Kildare Observer 1880-1935 are now available free online. This had been made possible courtesy of the Co. Kildare Archaeological Society and Kildare Library Services and is hosted by Irish Newspaper Archive. Both can be search separately or together, offering great access for researchers to an amazing treasure trove of Co. Kildare based information.
United Kingdom
National Library of Wales: Free online access to 15 million Welsh and English Language newspaper articles
Worldwide
Wikipedia:List of online newspaper archives: This is a list of online newspaper archives and some magazines and journals, including both free and pay wall blocked digital archives.
British Library open newspaper catalogue : This public domain dataset lists metadata list of all British, Irish, British Overseas Territories and Crown Dependencies newspapers held by the British Library.
British Library Newspaper Title-level List : This open access list lists the entire catalogue of world newspapers held by the British Library. Included are start and end years of publication, the places of publication (city, country, coverage, continent), variant titles and editions, and the language of publication.