Irwin's widow Terri and her two children appeared in public for the first time since the daredevil naturalist's death in a freak stingray attack two weeks ago to hear a wave of emotional tributes to the Aussie hero.
Australian Prime Minister John Howard opened the public memorial service at Irwin's beloved Australia Zoo in northeastern Queensland state, and movie stars including Russell Crowe, Cameron Diaz and Hugh Jackman offered video tributes.
Bindi brings crowd to tears
But it was Irwin's poised eight-year-old daughter, Bindi, who brought the audience of 5,000 VIPs and members of the public to their feet and to tears when she hailed her dad's work and vowed to follow in his footsteps.
"My daddy was my hero — he was always there for me when I needed him, he listened to me and taught me so many things, but most of all he was fun," the youngster, clad in a khaki safari suit made famous by her dad, told the crowd.
"We filmed together, caught crocodiles together, loved being in the bush together. I don't want daddy's passion to ever to end. I want to help endangered wildlife just like he did.
"Daddy made this place his whole life and now it's our turn to help daddy," Bindi told the cheering crowd cramming the "Crocoseum" of the Australia Zoo, where Irwin once wrangled all manner of dangerous reptiles.
Terri Irwin, wearing dark glasses and also clad in her husband's signature khaki, clutched their two-year-old son throughout the ceremony but did not speak.
Irwin's dad Bob choked back tears as he said goodbye to his celebrity offspring.
"Please don't grieve for Steve — he's at peace now. But I'd like you to grieve for the animals, for the animals have lost the best friend they ever had and so have I," he said in a brief speech.
Organisers said earlier that the ceremony would be watched live across Australia and around the world by around 300 million people, reflecting the extraordinary impact of the television conservationist.
Slick service
The public memorial, which took place more than two weeks after he was killed when a stingray's barb pierced his chest as he snorkelled on the Great Barrier Reef on September 4, was slick, fast-paced and punctuated by a flurry of action-packed video clips featuring Irwin, set to music.
During the one-hour ceremony tagged with the slogan "He changed our world," Irwin was hailed in songs as a "hero" and an "action man," while speakers lauded him as a great father and conservation researcher.
"There are 20 million pairs of Australian arms reaching out to embrace you this morning," Howard told Irwin's family, praising the ebullient conservationist's "quality of being genuine, being authentic" and his "great zest for life".
Thousands of fans who queued overnight last week to snap up the 3,000 public tickets to the show began streaming into Australia Zoo about two hours before the ceremony started.
A heavy police presence surrounded the zoo in the town of Beerwah in north-eastern Queensland, while roads in the area were clogged by the vehicles of more than 5,000 mourners who came from across Australia.