"This award belongs to them, not to me," said Harry, although he added that he welcomed the chance to highlight the resilience and achievements of Invictus participants and their families.
"Moments like these help us reach those that need Invictus most," said the prince, the younger son of King Charles III who was accompanied by his wife, Meghan, the Duchess of Sussex, at the sports awards ceremony in Los Angeles.
A former British army captain who served two tours of duty in Afghanistan, Harry launched the Invictus Games for wounded, injured or sick service personnel, those still serving as well as veterans.
The award is named for Pat Tillman, who gave up his successful NFL career to join the US Army Rangers after the September 11, 2001, attacks and was killed in Afghanistan in 2004 in what was later found to be a "friendly fire" incident.
Tillman's mother, Mary Tillman, had criticized broadcaster ESPN, creator of the Espys, for selecting the prince as the award recipient, saying there were others in the veteran community without the "money, resources, connections or privilege that Prince Harry has."
Harry thanked Tillman's widow, Marie, for attending the ceremony and also acknowledged "the Tillman family, especially Mrs. Mary Tillman, Pat's mother.
"Her advocacy for Pat's legacy is deeply personal and one that I respect.
"The bond between a mother and son is eternal and transcends even the greatest losses," said Harry, who was 12 when his mother, Princess Diana, died in a car crash in 1997.
