Australia is expected first to purchase American Virginia class attack submarines, which will be delivered in the early 2030s.

Source: https://news.antiwar.com/2023/03/09/us-navy-wants-to-turn-australia-into-a-full-service-submarine-hub/

Reuters has reported Australia is expected to buy up to five U.S. Virginia class submarines in the 2030's, before building a new British-designed submarine in South Australia under a partnership with both countries dubbed AUKUS.

Source: https://gazette.com/news/us-world/analysis-nuclear-submarine-plan-aims-to-give-australia-strategic-edge-to-deter-china/article_7402c8ed-9f6e-5ce6-b1a0-fd7cb170bfbf.html

Three conventionally armed, nuclear-powered Virginia class vessels will be sold "over the course of the 2030s," with the "possibility of going up to five if that is needed," Sullivan said.

Source: https://www.legit.ng/business-economy/1524954-australia-buy-nuclear-subs-ambitious-pact/