4 ms·Who Has the World's No. 1 Economy? Not the U.S4 points by mleonhard 9y agocdancette 9y agoTLDR: it's Chinanabla9 9y agoMeasured by GDP (PPP) in 2016 China was the largest economy, EU was the second , US was the third. It's important to consider EU as economy because EU negotiates trade deals as single entity. Brexit makes US second again, I think.