Exhibit 8.1

List of subsidiary companies

At 31 December 2023

The principal operating subsidiary companies of the Rio Tinto Group are listed in Note 30 to the 2023 Financial statements. The principal intermediate holding companies and group finance companies are as follows:

Company and country of incorporation	Principal activities	Class of shares held	Proportion of class held	Group interest
			%	%
Australia
Hamersley Holdings Limited	Holding company	A$ Ordinary shares	100	100
North IOC Holdings Pty Ltd	Holding company	A$ Ordinary shares	100	100
North Limited	Holding company	A$ Ordinary shares	100	100
Pacific Aluminium Pty. Limited	Holding company	A$ Ordinary shares	100	100
Peko-Wallsend Pty Ltd	Holding company	A$ Ordinary shares	100	100
Rio Tinto Finance Limited	Finance company	A$ Ordinary shares	100	100
Rio Tinto Finance (USA) Limited	Finance company	A$ Ordinary shares	100	100
Rio Tinto Investments One Pty Limited	Holding company	A$ Ordinary shares	100	100
Rio Tinto Investments Two Pty Limited	Holding company	A$ Ordinary shares	100	100
Robe River Limited	Holding company	A$ Ordinary shares	100	100
Bermuda
North IOC (Bermuda) Holdings Limited	Holding company	US$1.00 Ordinary shares	100	100
North IOC (Bermuda) Limited	Holding company	US$1.00 Ordinary shares	100	100
		US$100,000.00 Preferred shares	100	100
	US$143.64 Class A Ordinary shares		100	100
QIT Madagascar Minerals Ltd.	Holding company	US$1.00 Ordinary shares	100	100
Canada
Rio Tinto Canada Inc	Holding company	CA$ Class B shares	100	100
		CA$ Class C shares	100	100
		CA$ Class D shares	100	100
		CA$ Class J shares	100	100
		CA$ Class S shares	100	100
Netherlands
Oyu Tolgoi Netherlands BV	Holding company	€100 Ordinary shares	100	100
Rio Tinto Eastern Investments B.V.	Holding company	€12,510,234,217.00 Ordinary shares	100	100
			100	100
South Africa
Richards Bay Mining Holdings (Proprietary) Limited	Holding company	ZAR1.00 Ordinary shares	100	100
		ZAR1.00 B Ordinary shares	100	100
Richards Bay Titanium Holdings (Proprietary) Limited	Holding company	ZAR1.00 A Ordinary shares	100	100
		ZAR1.00 B Ordinary shares	100	100
United Kingdom
Rio Tinto Copper Holdings Limited	Holding company	US$1.00 Ordinary shares	100	100
		US$1.00 Preference shares	100	100
Rio Tinto Copper Limited	Holding company	US$1.00 Ordinary shares	100	100
Rio Tinto European Holdings Limited	Holding company	£1.00 Ordinary shares	100	100
Rio Tinto Finance plc	Finance company	£1.00 Ordinary shares	100	100
		US$1.00 Ordinary shares	100	100
Rio Tinto Finance (USA) plc	Finance company	£1.00 Ordinary shares	100	100
Rio Tinto International Holdings Limited	Holding company	£1.00 Ordinary shares	100	100
Rio Tinto Simfer UK Limited	Holding company	US$1.00 Ordinary shares	100	100
United States of America
Rio Tinto America Holdings Inc.	Holding company	US$0.01 Class A Common shares	100	100
		US$100.00 Series A Preferred Stock	100	100

Company and country of incorporation	Principal activities	Class of shares held	Proportion of class held	Group interest
Rio Tinto America Inc.	Holding company	US$100.00 Common shares	100	100
Rio Tinto Finance (USA) Inc.	Holding company	US$1.00 Common shares	100	100
Rio Tinto Minerals Inc.	Holding company	US$0.01 Common shares	100	100
Rio Tinto Technology Holdings Corporation	Holding company	US$ Common shares	100	100