Close friend and television personality Richard Wilkins gave the opening eulogy for the 47-year-old star, who was found dead in her Sydney apartment last Saturday after a well-publicised battle with depression.
"Charlotte was, as we all know, one in an absolute million - an original. She touched us all and she made our world a much better place," he said.
Wilkins said he wished they were not gathered today.
"But here we all are, putting on a brave face," he said.
"Today is a celebration of a wonderful and spectacular life of one of the most beautiful and generous, sharp and witty, sparkling and effervescent, honest and uncompromising people ever put on the planet."
Dawson's sister Vicky Dawson reportedly drew laughter as she presented an urn containing Charlotte's ashes, saying: "And here she is with us."
The star had always managed to stay beautiful, she said. "And in our minds you will always stay that way."
Ms Dawson told mourners her sister had been cremated in an orange Alex Perry dress at a private family ceremony on Wednesday, the Daily Telegraph reported.
Perry, who was among numerous fashion designers at the service, said Dawson was a friend who always made him laugh.
"She was a thoughtful, funny, beautiful, fragile girl who wanted to be loved."
The designer also lashed out at the online trolls who had bullied her on social media.
"No one has the right to say that to another human being - it's not okay, it's not on."
Among the mourners were singer Delta Goodrem, media magnate Lachlan Murdoch and wife Sarah, and a bevy of models including former Miss Universe Laura Dundovic.
Dawson's ex-husband, swimmer Scott Miller, was not present.
A service is expected to be held for Dawson's friends and family in New Zealand at a later date.
Measures to take
Charlotte Dawson confronted bullying in her life. This is what you can do:
Social media/online:
• Contact internet safety group NetSafe and ask for advice. NetSafe is in touch with sites such as Facebook and also the police.
• Make use of privacy settings and block a person from getting access to your social media page.
• If the bullying is of a threatening nature or becomes frequent, contact police. Save the messages so you can show police, but do not reply to bully.
• Tell a friend, parent, teacher or other trusted adult.
Bullying via cellphone:
• Text/call bullying: Don't reply or answer the phone. Block the number. Most telcos give customers an option of blocking phone numbers. You can do this on your phone when editing a contact or call your cellphone provider and ask them to do it. Blocking a number will stop you from receiving any messages, calls or pxts from that particular contact. They will not know they have been blocked.
Where to get help
• Lifeline: 0800 543 354
• Depression helpline (8am to 12 midnight): 0800 111 757
• Healthline - 0800 611 116
• Suicide Crisis Helpline (aimed at those in distress, or those who are
concerned about the wellbeing of someone else): 0508 828 865
• Youthline: 0800 376 633, free text 234
• Kidsline (aimed at children up to 14 years of age; 4pm to 6pm weekdays): 0800 543 754 (0800 kidsline)
