"It said: 'the buck stops here'," Father Kevin Dillon told Costa's state memorial service in the Victorian city on Wednesday.

"That was, and remains, the mark of true character."

Hundreds gathered at Kardinia Park, the headquarters of Costa's beloved Geelong Football Club, for the memorial service.

Dillon and others including acting Victorian Premier James Merlino paid tribute to the Cats' long-time president and renowned philanthropist and businessman.

Costa died in his sleep on May 2 after a year-long battle with illness, aged 83.

But his legacy would live forever, both at the football club and in the Geelong community, Dillon said.

"Frank would step up with no fanfare but with great effect," he said.

"Frank would follow his motto of 'character first'.

"Patron, benefactor, wise counsellor, generous contributor - Frank was there for the people of Geelong and Victoria."

Costa, who served at the Geelong Football Club for 30 years, is the only person named a legend of the club without ever playing for the Cats.

During his presidency, Geelong went from a financially battling club to a powerhouse that broke a 44-year AFL premiership drought in 2007 - adding two more flags in 2009 and 2011.

The breakthrough 2007 premiership remained his favourite, Dillon said, recalling celebrations at the club's base.

"The biggest smile of all was Frank's," he said.

"He was so proud and thankful that that cup ... was in Geelong.

"Most of all, because what it meant and was giving to the people of Geelong.

"The smiles of the people ... meant the world to Frank because it was that connection with the ordinary person that meant so much to him."

Costa's long-time friend and business associate Lindsay Fox said in his early 30s, he travelled overseas every second month.

"And every location I went to, I had a postcard for that city," Fox said.

"I directed it to Frank and addressed it 'the King of Geelong'. And it always got to him.

"His life was all about making things happen ... the satisfaction of giving and not receiving is one of the special features of Frank."

Costa is survived by his wife Shirley and eight children.

Australian Associated Press