Peripheral cannabinoid CB1 receptor antagonists that lack central nervous system effects are emerging as promising therapies for metabolic disease, yet the role of endothelial CB1 signaling in atherosclerosis remains unclear. Here, we show that endothelial CB1 is expressed in human atherosclerotic plaques, is induced by oscillatory shear stress in atheroprone flow regions, and promotes vascular inflammation, permeability and lipid uptake. Endothelial-specific Cnr1 deletion or peripheral CB1 antagonism in mice attenuates atherosclerosis, reduces endothelial caveolae-dependent low-density lipoprotein uptake by downregulating caveolin-1 and ALK1 expression, and improves metabolic parameters in brown and white adipose tissue and the liver. The anti-atherogenic and metabolic effects are more pronounced in females, which is possibly linked to estrogen signaling. These findings identify endothelial CB1 as a proatherogenic, sex-biased regulator of vascular lipid transport and plaque development and associated metabolic dysfunction.