Abunayyan is the founder and chairman of ACWA Power, a Saudi power generation and water desalination firm. He founded the company in 2004 and took it public on the Saudi stock exchange in 2021; he now owns 4.5% of the shares. Abunayyan also chairs Vision Invest, a Saudi holding company that owns stakes in several publicly traded and privately held companies. He also owns 8% of Abdullah Abunayyan Trading Company, a Saudi holding company that owns 50% of Vision Invest. Vision Invest and Abunayyan Holding own shares in several Saudi publicly traded companies in wastewater treatment, logistics, and flour milling.