The 33-year old finished the regular season on 17 goals, one ahead of Colorado Rapids striker Conor Casey.
Cunningham becomes the fifth player to win the award twice joining New England Revolution’s Taylor Twellman, Guatemala international Carlos Ruiz, current Crystal Palace striker Stern John and former USA international Roy Lassiter.
His 17-goal total surpassed his previous career-high of 16 goals, which he accomplished twice - with Real Salt Lake in 2006 and the Columbus Crew in 2002. Cunningham’s 16-goal campaign in 2006 earned him his first Golden Boot award.
Cunningham is second all-time on the career goal-scoring list with 121 regular season goals, just 10 behind D.C. United forward Jaime Moreno.