Pastor Miles McPherson of the Rock Church led the service, which included tributes from family members, a slideshow and a world-famous Polynesian Christian band. The Katinas, reportedly Seau's favorite group, were flown in for the funeral.
Members of Seau's family and former teammates, including LaDainian Tomlinson, were among those packing a church for the funeral, followed by burial at Eternal Hills cemetery.
Seau, considered the best linebacker of his generation, died from a self-inflicted gunshot wound to the chest on May 2. He played parts of 20 seasons in the NFL, with the San Diego Chargers, Miami Dolphins and New England Patriots.
Around 20,000 people took part in a public memorial for the late football star in the San Diego Stadium where he played for 13 years.
"Don't be sad today, be happy. Because Junior lives through us. Everybody in here," said Tomlinson.
Others in attendance included legendary quarterbacks John Elway, Peyton Manning and Dan Fouts, who remembered meeting the stand-out high school athlete for the first time.
"I wanted to make sure they pronounce his name correctly, so I asked him, 'How do I say your name?' He said, 'It's Seau. Because if I tackle someone, they say oww," said Fouts.
But most of the time was spent honoring Seau's community work with children.
Very little was said of the fact that Seau committed suicide, but Fouts did say a lesson should be learned by all, that everyone needs help sometimes and everyone should be better about communicating feelings and taking care of the community.
KGTV and The Associated Press contributed to this report.