Almost 200 Crown casino workers have received $1.2 million in back pay from the entertainment giant and a search is on for others who are owed money.
The company must also pay $350,000 to the Commonwealth Consolidated Revenue Fund after it signed an enforceable undertaking with the Fair Work Ombudsman.
Impacted staff worked in a variety of roles at Crown's Melbourne and Perth casinos including as food and beverage supervisors, concierges, receptionists, administrative workers, hairdressers and massage therapists.
The casino incorrectly classified them as award-free from July 2014 until June 2020.
The group should have had higher salaries and entitlements, including penalty rates, with amounts paid back ranging from $5 to $66,714.
So far 192 workers have been paid but the company is searching for eight others who must claim the money within the next 180 days.
Fair Work Ombudsman Sandra Parker hit out at the long-running underpayments of staff.
"All employers need to invest the time and resources to ensure they are meeting all lawful entitlements," Ms Parker said.
The company apologised and agreed to independent audits for the next three years.
"Crown takes its obligations as an employer seriously and self-reported to the Fair Work Ombudsman in 2020 following a comprehensive payroll review," Crown said in a statement.