Jack (354) remained the most popular boys name for the 13th consecutive year with Noah (299) jumping from seventh place to second.
Julie Ramsay, vital events statistician, said: “We can see from the 2020 names lists that different generations of parents have different preferences for naming their babies.
“Isla, the most popular name for girls in 2020, was the most popular name with mothers aged 35 and over, but it only ranked seventh with mothers aged under 25.
“However, Olivia, the most popular girls name of 2019, was ranked first by younger mothers and sixth by older mothers.
“Jack, the most popular name for boys in 2020, was the second most popular name with mothers aged 35 and above, and only 17th with mothers aged under 25.
“James was the most popular name for boys with older mothers while Noah was ranked first for younger mothers.”
But the year 2020 also brought the highest ever number of different names in what the NRS has described as a continuing trend.
While Isla was the top name for girls, one baby has the spelling Iyla – and there were other unusual spellings for Caldonia and Indya.
Among the other unique girl names are: Cleopatra, L-Elizabeth, Priscilladonna, Savvy, Temperance, Wing and You; with some foodie-themed names such as Margherita and Peaches.
Last year’s list contained a boy called Excel, with a 2020 parent having an Excell instead.
There were also boys called C, C-Jay, J and Jay-J; sports-themed names including Caddy, Lennie and Ricksen; plus Divinity, Fitz-Kiing, Jettison and Marvel.
Ms Ramsay added: “Popular culture often affects how people name their babies.
“The name Billie rose in popularity by 79% in the past two years with 34 baby girls being given this name in 2020.
“In the same time, Google searches in the UK for Billie and Billie Eilish spiked, with the singer having her first number one single in the UK in early 2020.
“Tommy, a name occurring in the popular TV shows Peaky Blinders and Love Island, has doubled in popularity in the last two years, with 148 boys being given this name.
“Our data shows it is more popular with younger mothers than with older mothers.”