Turnbull, who recently became the 29th Prime Minister of Australia, said "I am pleased to provide this message for Diwali celebrations in 2015."
"Diwali is a time to gather with family and friends and reflect on the meaning of this festive time -– the triumph of light over darkness," Turnbull said adding that the ancient tradition was marked by dancing, celebration and good food, combined with prayer and reflection.
He said that the lighting of lamps was a reminder of the shared commitment to a brighter future.
"During Diwali we remember that cultural expression is an important element in our society. For many, it provides meaning, purpose and inspiration to their daily lives," Turnball said.
"It enriches and enlivens our society, giving a greater texture and depth to the backdrop of modern life. Australia has long been an exemplar of how people of different faiths and cultures can live harmoniously together and find unity in diversity," he said.
"Our country is a beacon of hope and optimism for people of all faiths as well as those with none. I wish everyone an enjoyable Diwali," he added. Meanwhile, Diwali was celebrated across major cities, including Melbourne and Sydney, by the large Indian diaspora living there.
In Sydney, the Opera House will light up in a golden orange to mark Diwali festival on Thursday.
"Diwali has become a festival that is not only recognised, but embraced by Australians of all backgrounds," New South Wales Premier Mike Baird said in a message.
"The Indian community has always been forthcoming in welcoming community participation in festivals such as Diwali, and leads by example in its promotion of cultural acceptance and understanding," Baird said. "I encourage everyone to visit the Harbour foreshore to see our world famous icon light up for Diwali, to celebrate the symbolic victory of good versus evil and light over darkness," he said.