This data release includes 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Janub Metamorphic Complex in Southern Jordan. Rock samples were collected by Hind Ghanem of the University of Jordan. Muscovite-rich microcores were drilled from a polished thick section of a deformed granitoid and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. The 40Ar/39Ar data constrain the timing of formation of the foliation defined by muscovite.