In his second campaign with LAFC, Vela broke 2018 MLS MVP Martinez's standard for goals in a season with 34, guiding the team to the Supporters' Shield and a regular-season record of 72 points.
The 72-time capped Mexican international became the quickest to 20 goals in a season (21 matches) and finished the term on a nine-game scoring streak that included a hat-trick on the final matchday against the Colorado Rapids.
Vela's combined goals and assists haul of 49 this season is also an MLS record.
The 30-year-old becomes the first Mexican to win the honor. Former Chicago Fire and El Tri standout Cuauhtemoc Blanco finished third in MVP voting in 2007 and 2008.