Flags of Queen Elizabeth were lowered across the country.
Barbados has removed Queen Elizabeth as the head of state and declared itself a republic.
This marks the first time a country has removed the Queen since Mauritius in 1992.
The declaration came following a ceremony in the capital city of Bridgetown, marking 55 years since the country first achieved independence.
The move to becoming a republic marks the end of a connection between the countries since British ships first arrived in the 1600s.
Dame Sandra Mason has been sworn in as the country's first president, replacing Queen Elizabeth as the head of state.
"Vessel Republic Barbados has set sail on her maiden voyage. May she weather all storms and land our country and citizens safely on the horizons and shores which are ahead of us," she said during her inauguration ceremony.
As part of the ceremony, Barbadian singer Rihanna was declared a national hero by President Mason.
"May you continue to shine like a diamond and bring honour to your nation," said Prime Minister Mia Mottley.
Prince Charles attended the event as a guest of honour to oversee the handover.
In a speech during the ceremony, the Prince of Wales acknowledged the impact that slavery had on the nation since the arrival of colonisers.
Barbados had acted as a central trading hub during slavery until the abolishment of the act in 1834.
"From the darkest days of our past, and the appalling atrocity of slavery, which forever stains our history, the people of this island forged their path with extraordinary fortitude," said Prince Charles.
Following the departure of Barbados, there are now 15 countries in the Commonwealth, including Australia, New Zealand, Canada, Jamaica and the Bahamas.
