The Australian Prime Minister known for pioneering social welfare efforts in the late 20th century was Bob Hawke. Serving from 1983 to 1991, Hawke implemented significant reforms that aimed to improve living standards and reduce inequality. Under his leadership, initiatives such as the introduction of the Medicare system revolutionized healthcare access, ensuring that Australians received necessary medical services despite their economic circumstances. Additionally, his government focused on education reform and labor rights, cementing his legacy as a key figure in enhancing social welfare in Australia.