The majority of Australia Day revellers in NSW behaved well and enjoyed the festivities in safety, although around 100 people were arrested and charged after going too far, police say.
Adding to this was a separate police operation targeting the Big Day Out at Sydney Olympic Park where more than 120 people were arrested and charged with drug and other offences.
More than 2000 officers were deployed across the state in Operation Shoreline on Sunday, targeting anti-social behaviour and alcohol-related crime as people celebrated Australia Day.
During the operation, 100 people were arrested and charged with a total of 127 offences including assault, affray, assault/hinder police, offensive behaviour, breach bail and drink-driving, police said.
Operation Shoreline Commander, Assistant Commissioner Mark Murdoch, said the majority of people enjoyed Australia Day events without incident and returned home safely.
"The small number of people that chose to do the wrong thing were targeted and swiftly dealt with by police," he said in a statement.
Mr Murdoch said excessive alcohol consumption was again of concern and he urged those continuing celebrations on Monday to do so responsibly and stay safe.
More than 30,000 music fans attended the Big Day Out at Sydney Olympic Park where drug-detection dogs conducted more than 570 searches of people and police arrested and charged 122 revellers.
Of those, 71 were charged with drug possession and two for drug supply, while 25 people were issued with cannabis cautions and three were charged for offensive behaviour.
Police also seized alcohol from ticketholders on their way to the festival, with 10 under-aged youths dealt with over alleged possession of liquor.
Hundreds of people were also refused entry or ejected from the venue for inappropriate and anti-social behaviour, police said.
South West Metropolitan Region Commander, Assistant Commissioner Frank Mennilli, said the majority of people enjoyed their Big Day Out safely.
"It was disappointing to see that some people in the crowd refused to heed our warnings and insisted on doing the wrong thing.
"We continually reminded ticketholders that prohibited drugs were not only illegal, but also highly dangerous and potentially life-threatening, yet some still believed they were above the law," Mr Mennilli said.