Exhibit 8.1

List of subsidiary companies

At 31 December 2014

The principal operating subsidiary companies of the Rio Tinto Group are listed in Note 34 to the2014 Financial statements. The principal
intermediate holding companies and group finance companies are as follows:



|                                             |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|-------------------------------------------- |  | ------------------- |  | ------------------------------------ |  | ---------------------- | --- |  | ------------- |  | --- | 
|Company and countryof incorporation          |  | Principalactivities |  | Class ofshares held                  |  | Proportionof classheld |     |  | Groupinterest | 
|                                             |  |                     |  |                                      |  | %                      |     |  | %             | 
|                                             |  |                     |  |                                     
|Australia                                    |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Australian Coal Holdings Pty Limited         |  | Holding company     |  | A Class                            |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Hamersley Holdings Limited                   |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|North IOC Holdings Pty Limited               |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|North Limited                                |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Pacific Aluminium Pty Limited                |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Peko-Wallsend Pty Limited                    |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto (Commercial Paper) Limited         |  | Finance company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Finance Limited                    |  | Finance company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Finance (USA) Limited              |  | Finance company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Investments One Pty Limited        |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Investments Two Pty Limited        |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|Robe River Limited                           |  | Holding company     |  | Ordinary shares                      |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|Bermuda                                      |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|North IOC (Bermuda) Holdings Limited         |  | Holding company     |  | Ordinary shares of BMD 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|North IOC (Bermuda) Limited                  |  | Holding company     |  | Ordinary shares of BMD 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|QIT Madagascar Minerals Ltd.                 |  | Holding company     |  | Ordinary shares of USD 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|Canada                                       |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|46117 Yukon Inc.                             |  | Holding company     |  | Common shares                        |  |                        | 100 |  |               |  | 100 | 
|535630 Yukon Inc                             |  | Holding company     |  | Common shares                        |  |                        | 100 |  |               |  | 100 | 
|7999674 Canada Inc.                          |  | Holding company     |  | Common shares                        |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Canada Inc                         |  | Holding company     |  | Class B shares no par value          |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | Class C shares no par value          |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | Class D shares no par value          |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Finance Canada Inc.                |  | Finance company     |  | Common shares                        |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|Namibia                                      |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Skeleton Coast Diamonds Limited              |  | Holding company     |  | Shares of NAD 2.00 each              |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|Netherlands                                  |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Oyu Tolgoi Netherlands BV                    |  | Holding company     |  | Ordinary shares of EUR 100.00 each   |  |                        | 65  |  |               |  | 51  | 
|                                             |  |                     |  |                                     
|Rio Tinto Eastern Investments BV             |  | Holding company     |  | Ordinary shares of EUR454.00 each    |  |                        | 100 |  |               |  | 100 | 
|Turquoise Hill Netherlands Cooperatif UA     |  | Holding company     |  | Ordinary shares of EUR 100.00 each   |  |                        | 100 |  |               |  | 51  | 
|                                             |  |                     |  |                                     
|South Africa                                 |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Richards Bay Mining Holdings (Pty) Limited   |  | Holding company     |  | Ordinary shares of ZAR1.00 each      |  |                        | 100 |  |               |  | 100 | 
|Richards Bay Titanium Holdings (Pty) Limited |  | Holding company     |  | A Ordinary shares of ZAR 1.00 each   |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | B Ordinary shares of ZAR 1.00 each   |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|United Kingdom                               |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Rio Tinto European Holdings Limited          |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Finance plc                        |  | Finance company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto International Holdings Limited     |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Investments Limited                |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Namibian Holdings Limited          |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Overseas Holdings Limited          |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Simfer UK Limited                  |  | Holding company     |  | Ordinary shares of USD 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Western Holdings Limited           |  | Holding company     |  | Ordinary shares of GBP 1.00 each     |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | Preference shares of AUD 100.00 each |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  | Preference shares of USD 90.00 each  |  |                        | 100 |  |               |  | 100 | 
|                                             |  |                     |  |                                     
|United States of America                     |  |                     |  |                                      |  |                        |     |  |               |  |     | 
|Rio Tinto America Holdings Inc.              |  | Holding company     |  | Common shares of USD 0.01 each       |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto America Inc.                       |  | Holding company     |  | Common shares of USD 100.00 each     |  |                        | 100 |  |               |  | 100 | 
|Rio Tinto Minerals Inc.                      |  | Holding company     |  | Common shares of USD 0.01 each       |  |                        | 100 |  |               |  | 100 |