Notice to ASX/LSE

Exhibit 99.21

Bank of America Merrill Lynch Metals & Mining Conference

14 May 2019

Rio Tinto chief executive J-S Jacques is presenting today at the Bank of America Merrill Lynch Metals & Mining Conference in Barcelona, Spain.

The presentation is attached and will also be available at riotinto.com/presentations, along with the audio webcast details.

Contacts

media.enquiries@riotinto.com riotinto.com

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