Ben and Clarissa Love were delighted by their first child's arrival at 8.47am on New Year's Day.
At her birth, Arlo Brooklyn Love weighed 3.6 kgs and was 50 cm long.
Mum Clarissa said she went into labour on New Year's Eve, which was exactly the date her daughter was due to be born.
"Arlo arrived 21 hours later," she said.
"All the midwives were absolutely amazing."
An estimated 371,504 babies were born around the world on New Year's Day, according to UNICEF.
Fiji in the Pacific welcomed 2021's first baby and the United States welcomed its last. Globally, over half of these births are estimated to take place in 10 countries: India (59,995), China (35,615), Nigeria (21,439), Pakistan (14,161), Indonesia (12,336), Ethiopia (12,006), the United States (10,312), Egypt (9,455), Bangladesh (9,236) and the Democratic Republic of the Congo (8,640).
In total, an estimated 140 million children will be born in 2021. Their average life expectancy is expected to be 82 years.