Indian veteran Raj held the women's record with an unbeaten 114 against Ireland in 1999 at the age of 16 years and 205 days.
Ireland's Amy Hunter on Monday became the youngest player to score an ODI century, striking an unbeaten 121 to take her side to a win against Zimbabwe on her 16th birthday in Harare, bettering the record previously held by India's Mithali Raj. (More Cricket News)
The schoolgirl from Belfast overtook the record previously held by India's Mithali Raj, who scored 114 not out against Ireland at the age of 16 years and 205 days in June 1999.
Hunter, playing only her fourth ODI, struck right boundaries in her 127-ball knock as Ireland beat Zimbabwe by 85 runs.
Indian veteran Raj held the women's record with an unbeaten 114 against Ireland in 1999 at the age of 16 years and 205 days.
Raj, 38, continues to play in the ODI and Test formats, leading the Indian teams in both.
"It feels really good -- it's a bit surreal," said the teenager from Northern Ireland.
"I didn't really know what to think when I was coming up to my fifty. I just wanted to stick by and get there.
"When I reached my hundred, I had no idea what to do, whether to take the helmet off or keep it on. It was unbelievable."
Hunter made her international debut against Scotland in May aged 15.
She is just the fourth woman to hit an ODI century for Ireland and the first since 2000.
The youngest male batter to score an ODI century remains Pakistan's Shahid Afridi, who scored 102 against Sri Lanka in 1996 aged 16 years and 217 days.