Measurements of bottomonium production in heavy-ion and p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The inclusive yield of the three Υ states, Υ(1S+2S+3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au+Au and p+p collisions at sNN=200 GeV. The Υ(1S+2S+3S)→e+e− differential cross section at midrapidity was found to be Beedσ/dy=108±38(stat)±15(syst)±11(luminosity) pb in p+p collisions. The nuclear modification factor in the 30% most central Au+Au collisions indicates a suppression of the total Υ state yield relative to the extrapolation from p+p collision data. The suppression is consistent with measurements made by STAR at RHIC and at higher energies by the CMS experiment at the Large Hadron Collider.