While it remains debated if the mineral deposits mined for phosphorus fertilizer are running out, phosphorus insecurity is an emerging global issue. We explore how it is linked to the current linear phosphorus economy (LPE) and the historic and current implications. The problems are multifold: there are geopolitical concerns over phosphorus deposits held only by a few nations, sharply rising costs of phosphorus fertilizers, heavy metal contaminants affecting soil and food, problematic phosphorus mining wastes, and the widespread environmental degradation caused by fertilizer inefficiencies. A new phosphorus economy can resolve these problems. Transitioning to a sustainable use of phosphorus demands a circular phosphorus economy (CPE). A CPE supports several Sustainable Development Goals and enables countries without phosphorus deposits to achieve greater phosphorus autonomy. We illustrate current problems with case studies and outline opportunities for change. The CPE will feature phosphorus recovery facilities, waste valorisation technologies, and improved fertilizer formulations that are customised to crop systems. We highlight examples of the rapidly advancing CPE that forms an integral part of the bioeconomy and the circular economy.