Kerr scored a brace for club side Chicago Red Stars in their 3-1 win against Washington Spirit to stretch her tally for the season to 18 goals, breaking her own single-season record of 17.
It caps off another massive season for the 26-year-old who is odds on to claim a third straight NWSL golden boot title.
With one game left to play, Kerr's tally of 18 goals is seven ahead of her nearest challenger.
The record is just one of a number of NWSL league best mark's held by the Matilda's captain including all-time best goalscorer with 69 goals, most goals in a game with 4 and most hat-tricks in a season with two.
Kerr's Red Stars will finish the regular season next Sunday morning (AEST) against Utah Royals.