Olivia Newton-John: Australia celebrates 'force of nature' performer
The 73-year-old died in August in the United States following a long battle with breast cancer.
Newton-John was best known for her role as Sandy in the iconic 1978 film Grease and for musical hits such as Physical.
Her daughter, Chloe Lattanzi, has said that her heart is "broken in two".
"I stand here before you so desperately wanting to feel strong and confident and speak eloquently but the truth is, I feel like a little girl lost without her mother," said Ms Lattanzi while fighting back tears at the service at Hamer Hall.
"She was my safe space, my guide, my biggest fan and the earth beneath my feet."
Newton-John's widower, John Easterling, also became emotional while talking about his late wife.
"We'd each had some hard times in our life before like everyone has and we're just talking about how lucky we were to have found each other," he said.
"Every day with Olivia was supernatural. Every day with Olivia was a bit of magic."
The singer Dannii Minogue said that Newton-John was the reason why she started performing and that the thought of her death was still sinking in.
Other celebrities paid tribute to the late star in video recordings played to the crowd at the memorial, including Sir Elton John, Mariah Carey and Pink.
Sir Elton described her as a "wonderful force of nature", while Dolly Parton, who sang with Newton-John several times, said she considered her a friend as well as a fellow performer.
"Olivia, to quote one of your songs - I honestly love you," said Parton.
The service ended with Australian singer Delta Goodrem singing a medley of Newton-John's hits.
Goodrem said being able to celebrate her life was "incredibly special".