Family, teammates and coaches were among several hundred people who gathered at a suburban Atlanta church for the 23-year-old's funeral.
McKinley died last week at his home near Broncos headquarters in Denver. Authorities believe he shot himself in the head because he was depressed after his second consecutive season-ending knee surgery.
Linebacker Wesley Woodyard was among several Broncos teammates who attended the service. He said McKinley came into the locker room and "taught 61 men how to laugh every day."
"If we ever had a hard moment, we always depended on Kenny to make us laugh," he said.
McKinley's parents, Kenneth and Karen, and sisters Kimberly and Kayla, were joined in their mourning Monday by many friends and family members.
"He chased his dream; he made his dream," John McKinley Jr. said of his nephew's arrival in the NFL. He said the player seemed "full of joy" when they had dinner shortly before his death.
McKinley was a football standout at South Cobb High School and a fifth-round draft choice out of South Carolina in 2009.
McKinley's high school coach, Derrick Cook, remembered a giving, loyal, thoughtful young man whose whole body would shake when he laughed.
"They say the brightest stars in the sky burn out the quickest. I wasn't sure I believed that until today," Cook said.
McKinley had a unique combination of toughness, intelligence and love of the game, South Carolina coach Steve Spurrier said.
"Everything he represented as a person and a player was tremendous," Spurrier said. "I'm always thinking about how I need to find another Kenny McKinley."