This study is the first comprehensive assessment of the global apparel industry’s contribution to plastic pollution. It includes leakage of packaging and end-of-life apparel waste in addition to fiber emissions during apparel production and use. We estimate that the apparel industry generated 9.2 [5.5 – 13] million tons (Mt) of plastic pollution in 2019, corresponding to 15% [6.3% – 31%] of the estimated 61 Mt from all sectors. The main source of plastic pollution from the apparel supply chain is synthetic clothing as mismanaged waste either in the country of its original use or in the countries receiving used apparel exports. A fundamental transformation of the apparel economy towards a circular framework along with decreased synthetic apparel consumption is needed to tackle apparel-related plastic pollution.