Balancing the state and the market, the third pillar (i.e., any association of people that is neither public nor private) is a key sector in society. In contrast to the first two pillars (the public sector and the private sector), the third pillar has received very little attention in academic and policy debates. This paper aims to facilitate research on the third pillar's relevance by constructing the first global dataset on the size of the third pillar, including estimates for 120 countries. Results show that the size of the third pillar is substantial, both when measured as third pillar time (TPT) or third pillar participation (TPP). Global TPT is equivalent to 5.1 percent of total employment, more than half of the global agricultural sector. Moreover, findings indicate that TPP equals 13.4 percent, suggesting that more than one person in eight of the world's adult population is active as a volunteer in the third pillar.