Whitehaven CEO Paul Flynn said Humphris brought more than 20 years' experience in the resources sector, with a diverse and deep background across open cut and underground operations.
"We are excited for Ian to be joining the company and the executive leadership team," he said.
"Ian is a proven leader, whose operational credentials are complemented by a successful track record of leading a large workforce with strategic oversight of multiple mining operations. Uniquely, his suite of skills and compelling diversity of experience will be invaluable as we deliver on the next phase of growth for the business."
Humphris joins Whitehaven from Peabody Energy Australia, where he held a broad range of senior roles covering many aspects of that business.
Most recently he was vice-president - health, safety and environment and previously held similar level roles managing the company's open cut operations, supply chain and infrastructure assets.
Humphris began his career in resources as a mining engineer in various Queensland mines before transferring to the New South Wales coalfields and working in senior roles for both mine owner and mining services provider, Thiess.
Granger will remain with Whitehaven until the end of the financial year and help with Humphris' integration into the management team and the business more broadly.