The award is named for the Pittsburgh superstar who was killed in a plane crash 39 years ago while helping take relief supplies to earthquake-ravaged Nicaragua. It honors a player who combines outstanding play on the field and work in the community.
After visiting children in his native Dominican Republic, the Boston slugger founded the David Ortiz Children's Fund last year. He received the award prior to the start of Game 2 of the World Series.
"Major League Baseball is pleased to present David Ortiz with the 2011 Roberto Clemente Award," Commissioner Bud Selig said. "David's remarkable commitment to helping children receive essential pediatric care in the United States and the Dominican Republic makes him a wonderful choice for this honor.
"The legacy of the great Roberto Clemente lives on through the selfless actions of players like David and so many of his peers."
Ortiz is the second player from the Red Sox to win the award in as many years. Last year's recipient was pitcher Tim Wakefield.