Blood vessel endothelial cells (EC) display heterogeneity across vascular beds, which is at the bases of organ specificity and anticipated to drive site-specific vascular pathology. It is assessed in vivo using transcriptomics, and in vitro using functional assays, but how proteomes compare across human in vitro cultured ECs remains incompletely characterized. We generated an in-depth human EC proteomic landscape (>8000 proteins) across 6 vascular beds and 2 in vitro models both in steady-state and upon IFNγ-induced inflammation. EC proteomes displayed a high similarity and organ specific proteins were limited. Variation between ECs and donors was mainly based in biological processes underlying proliferation and differentiation. BOECs and HUVECs represented the extremes of proteomic phenotypes. IFNγ responses were highly conserved across cellular sources. Harnessing dynamics in protein abundances we delineated interactor networks of VWF and VE-Cadherin. This EC landscape provides an extensive proteomic addition in studying EC biology and heterogeneity from an in vitro perspective.