Exhibit 8.1

List of subsidiary companies

At 31 December 2018

The principal operating subsidiary companies of the Rio Tinto Group are listed in Note 33 to the 2018 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
Australian Coal Holdings Pty. Limited		Holding company	AUD A shares		100		100
Hamersley Holdings Limited		Holding company	AUD A Class Ordinary shares		100		100
North IOC Holdings Pty Ltd		Holding company	AUD Ordinary shares		100		100
North Limited		Holding company	AUD Ordinary shares		100		100
Pacific Aluminium Pty. Limited		Holding company	AUD Ordinary shares		100		100
Peko-Wallsend Pty Ltd		Holding company	AUD Ordinary shares		100		100
Rio Tinto Finance Limited		Finance company	AUD Ordinary shares		100		100
Rio Tinto Finance (USA) Limited		Finance company	AUD Ordinary shares		100		100
Rio Tinto Investments One Pty Limited		Holding company	AUD Ordinary shares		100		100
Rio Tinto Investments Two Pty Limited		Holding company	AUD Ordinary shares		100		100
Robe River Limited		Holding company	AUD 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 (US$143.64126903)			100		100
QIT Madagascar Minerals Ltd.		Holding company	US$1.00 Ordinary shares		100		100
Canada
46117 Yukon Inc.		Holding company	CAD Common shares		100		100
			CAD Preferred shares		100		100
535630 Yukon Inc		Holding company	CAD Common shares		100		100
			CAD Preferred shares		100		100
7999674 Canada Inc.		Holding company	CAD Common shares		100		100
Rio Tinto Canada Inc		Holding company	CAD Class B shares		100		100
			CAD Class C shares		100		100
			CAD Class D shares		100		100
			CAD Class J shares		100		100
			US$Class K shares		100		100
Rio Tinto Diamonds and Minerals
Canada Holdings Inc.		Holding Company	CAD Class A shares		100		100
			CAD Class B shares		100		100
			CAD Class C shares		100		100
			CAD Class P1 Preferred shares		100		100
Namibia
Skeleton Coast Diamonds Limited		Holding company	NAD 2.00 Ordinary shares		100		100
Netherlands
Rio Tinto Eastern Investments B.V.		Holding company	€453.78 Ordinary shares		100		100
South Africa
Richards Bay Mining Holdings (Proprietary) Limited		Holding company	ZAR1.00 A 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 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 Namibian Holdings Limited		Holding company	£1.00 Ordinary shares		100		100
Rio Tinto Overseas Holdings Limited		Holding company	£1.00 Ordinary shares		100		100
			US$1.00 Ordinary shares		100		100
Rio Tinto Simfer UK Limited		Holding company	US$1.00 Ordinary shares		100		100
Rio Tinto Western Holdings Limited		Holding company	£1.00 Ordinary shares		100		100
			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
Rio Tinto America Inc.		Holding company	US$100.00 Common shares		100		100
Rio Tinto Minerals Inc.		Holding company	US$0.01 Common shares		100		100