A three-dimensional shaped article production method for producing a three-dimensional shaped article by ejecting a shaping material to a stage and stacking layers according to a path including multiple partial paths is provided. The production method includes a first step of specifying a gap portion occurring inside the three-dimensional shaped article based on first shaping data having data for shaping a first portion that is a part of the three-dimensional shaped article by stacking layers having a first thickness and data for shaping a second portion that is adjacent to the first portion in a direction orthogonal to a stacking direction of the layers with a layer having a second thickness corresponding to a thickness of the first portion, a second step of generating second shaping data from the first shaping data by changing the first shaping data so as to fill up the gap portion when the gap portion is specified, and a third step of shaping the three-dimensional shaped article by ejecting the shaping material according to the second shaping data.