Thousands of Australians gathered across the country in largely peaceful Invasion Day protests, as thousands of others became the nation's newest citizens and many marked Australia Day with traditional barbecues, picnics and trips to the beach.
Prime Minister Anthony Albanese used a national ceremony speech in the capital to call for unity while celebrating the "richness" of the nation's history.
"We all belong to the same proud story," he said.
"We are all part of a nation built by hope and hard work, aspiration and determination."
Many marked the day with a trip to the beach while families celebrated with a picnic and fired up barbecues.
'I see it as Invasion Day'
Thousands took part in protests across the country including Sydney, Melbourne, Brisbane, Adelaide and Canberra to highlight the concerns of Indigenous Australians and also held events that celebrated Indigenous culture.
Australia Day became a public holiday in 1994 and marks the day the First Fleet landed in Sydney Cove in 1788. But, many Australians, both Indigenous and non-Indigenous, consider it a day of mourning and refer to it as Invasion Day or Survival Day.
In Hobart, instead of a minute of silence, hundreds held what they called a 'minute of power', making noise by stomping their feet and chanting: "We won't celebrate Invasion Day."
In Brisbane, Uncle Barry Tenor from the Bidjara and Kamilaroi peoples described January 26 as "the last day of our happiness and the first day of our sorrows".
"I've been marching since the 70s, and today, it's just recognition that we are still around," he told NITV.
"A lot of people see January 26 as Australia Day; I see it as Invasion Day."
Trevor Winders, another protester in Brisbane, said it was important to turn up to the rally.
"I believe in Aboriginal rights, and we've got a long way to go. There's a bit of truth-telling that needs to be done,"
Indigenous Australian singer Shellie Morris AO performed with her band at a January 26 event in the Northern Territory, saying she has always been "conflicted" about the day.
"For me today, it was more about enabling my family to have a voice. And it didn't really matter which day it was," she said.
In Melbourne, the rally was held as part of the weekly pro-Palestinian protests.
In Adelaide, members of the neo-Nazi National Socialist Network were photographed by Getty Images as they were being arrested at a counter-protest to the Survival Day march.
South Australian police confirmed to SBS News they made a number of arrests of protesters unrelated to the Survival Day march.
A spokesperson said the individuals were in the process of being charged.
Newest citizens mark 'special moment'
Around 20,000 people from more than 100 countries became the newest Australian citizens on Sunday in citizenship ceremonies around the nation.
Balwand Singh Dhillon, who arrived in Australia in 2015 from India with a student visa, took his oath of citizenship in Perth and said he was proud to become Australian.
"I think this is the best country you live in by far," he told SBS News, saying he enjoyed multiculturalism.
"It is really a good feeling, and I can't put much words into it. It is a special moment."
In western Sydney, more than 200 people became citizens, some including Tien Huyn, fulfilling a long-held dream.
"It's taken maybe six and a half years, but today, my dream has come true," Huyn told SBS News.
Liberal leader criticises Invasion Day rallies
In a speech at Albury church in NSW, the deputy opposition leader Sussan Ley criticised Invasion Day rallies across the country and compared the arrival of the First Fleet to Elon Musk's SpaceX Mars mission.
"In what could be compared to Elon Musk's SpaceX's efforts to build a new colony on Mars, men in boats arrived on the edge of the known world to embark on that new experiment.
"And just like astronauts arriving on Mars those first settlers would be confronted with a different and strange world, full of danger, adventure and potential."
Albanese also criticised the Opposition leader Peter Dutton for not attending the National Australia Day event.
"Why wouldn't you participate in national events if you want to be a national leader? I'm here on Australia Day. And it's a pity that Peter Dutton isn't here," he said.
"Because what we have in common is so much greater than anything that any differences that people might have. I want those differences to be respectful."
In a social media video, Dutton said Australia Day was a celebration of "the greatest country in the world, and we shouldn’t be afraid of celebrating it".
He said its defining achievement has been the "weaving together" of the Indigenous, British and migrant threads.
"We have every reason to be patriotic and proud today. Let’s celebrate the achievement of Australia, under one flag," he said.
