A structural insulated building panel with a moisture barrier seal includes a structural insulated panel, a seal section, a first spline-receiving grove, and a second spline-receiving groove. The seal section is extended from a phenolic resin sheet of the structural insulated panel so that the seal section can be positioned in between multiple structural insulated panels in order to prevent moisture penetration. The seal section is adjacently positioned with the second spline-receiving groove of the initial structural insulated panel and extends into the first spline-receiving groove of the adjacent structural insulated panel during the installation of multiple structural insulated panels.