We report on multiwavelength observations, ranging from X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption lines due to O i,Si ii,and C iv, implying a likely redshift of z ¼1:547. The well-sampled light curves, in particular from 0.5 to 4 days after the burst, suggest a jet break at 3.7 days, corresponding to a jet opening angle of 7.0,andimplyinganintrinsicGRBenergyinthe1Y10,000keVbandofaroundE¼(6:3Y6:9);1051ergs(basedonthefluencesmeasuredbythegamma−rayde−tectorsoftheIPN).GRB070125isamongthebrightestafterglowsobservedtodate.TheSEDimpliesahostextinctionofAV3˘c0:9mag.Tworebrighteningepisodesareobserved,onewithexcellenttimecoverage,showinganincreaseinfluxof568000 s.The evolution of the afterglow light curve is achromatic at all times.Late-time observationsof the afterglow do not show evidence for emission from an underlying host galaxy or supernova. Any host galaxy would be subluminous, consistent with current GRB host galaxy samples. Evidence for strong Mg ii absorption features is not found, which is perhaps surprising in view of the relatively high redshift of this burst and the high likelihood for such features along GRB-selected lines of sight