A tearful Samuel Johnson struggled to speak after the actor and cancer research fundraiser was announced as Victoria's Australian of the Year.
The award comes just weeks after his beloved sister died from cancer.
"Connie and I always liked turning negatives into positives," he said when he accepted the award on Thursday night.
"I've got some plans that I'm working on and I'm trying to uphold my sister's legacy," Johnson said.
He apologised for being "useless" but said he would continue to put aside acting to focus on supporting cancer research.
The passionate cancer fundraiser co-founded charity Love Your Sister with his older sister Connie, who died in September after a long battle with the disease.
Johnson pedalled more than 15,000km on a unicycle around Australia, raising $1.4 million for the Garvan Research Foundation and has helped raise more than $7 million for his charity.
Thursday's announcement as Victoria's Australian of the Year for 2018 will help raise the profile of his charity and makes him a nominee for the national title in January.
Samuel Johnson is Victoria's nominee for Australian of the Year.— Daniel Andrews (@DanielAndrewsMP) October 26, 2017
Good luck, mate. This one's for Connie.
(P.S. We love you too, Magda.) pic.twitter.com/cmtpdjMYV0
In the Victorian awards, Johnson was up against fellow actor, author and marriage equality advocate Magda Szubanski.
She has won awards for her 2015 memoir Reckoning and has been applauded for standing up as a member of the gay and lesbian community and working with young people.
Bayside resident and founder of Ovarian Cancer Australia Karen Livingston and Mornington Peninsula animal advocate and investigator Lyn White were also nominated.
VICTORIAN AUSTRALIAN OF THE YEAR 2018 WINNERS:
* Senior Australian of the Year: Professor Paul Zimmet
The 75-year-old scientist and diabetes specialist predicted the global epidemic of Type 2 diabetes and has improved the lives of those living with the serious illness.
* Young Australian of the Year: Georgie Stone
The 17-year-old is a tireless campaigner for transgender youth. At age 10 she became the youngest person in the country to be granted permission by a court to take hormone blockers, the first stage of medical treatment for transgender children.