Marnie Finlayson is Managing Director of DevEx Resources and serves as a Non-Executive Director of Northern Star Resources. She is a highly respected leader in the Australian resources sector, with more than 25 years of experience spanning mining, minerals processing, project development and executive leadership. 

Prior to joining DevEx Resources in 2025, Marnie spent 17 years with Rio Tinto, where she held a range of senior operational and leadership roles across Australia and internationally. Most recently, she served as Managing Director of Rio Tinto’s Battery Materials business, leading the development of the company’s battery materials portfolio through strategic investments, partnerships and projects across North America, South America and Europe.  

A graduate of the Western Australian School of Mines (WASM), Marnie holds a Bachelor of Engineering (Minerals Engineering) with Honours. Marnie is passionate about the critical role of the resources industry in supporting the global energy transition, developing future industry leaders, and creating high-performing, values-driven workplaces.