The late positive potential (LPP), which is reduced following the use of reappraisal, is a potential neurosignature for emotion regulation capacity. This sensitivity of the LPP to reappraisal is rarely studied in children. We tested whether, in 26 typically developing seven- to nine-year-olds, LPP amplitudes were reduced following reappraisal and whether this effect varied with age and anxiety. For the full sample, LPPs were not significantly reduced following reappraisal. As predicted, reductions in the LPP following reappraisal were greater for older children and those showing less anxiety. The utility of the LPP as a neurosignature for emotion regulatory capacity is discussed.