Exhibit 99.1 Rio Tinto Group Unaudited Condensed Consolidated Interim Financial Report for the six months ended 30 June 2023 TABLE OF CONTENTS About Rio Tinto 1 Forward-looking statements 2 Interim results 2023 3 Progress against our strategy and objectives in 2023 4 Financial performance 6 Shareholders returns policy 12 Capital projects 13 Review of operations 16 Directors’ report for the half year ended 30 June 2023 24 Rio Tinto financial information by business unit 27 Alternative performance measures 31 ...