Jack Nicholson is one of the world's more famous 'Jacks'
Jack was once again the favourite name for baby boys born in the UK in 2008, making it the most popular choice for the 13th year in a row.
Girls' names showed more variation across the nations, with Olivia taking top spot in England, replacing Ruby.
Scots preferred Sophie, while Katie was top in Northern Ireland and Ruby was most popular in Wales.
Riley for boys and Lexi for girls were the fastest-growing choices, the Office for National Statistics said.
There were 708,711 live births in England and Wales during 2008, with 26,815 different boys' names and 34,043 different girls' names registered.
The full top 10 boys' names in England and Wales in 2008, in order of popularity, were Jack, Oliver, Thomas, Harry, Joshua, Alfie, Charlie, Daniel, James and William.
There were no new entries in the boys' top 10 from the previous year, although Oliver and Harry each rose a place, while Thomas and Joshua both dropped one.
The biggest climber in the top 10 was Alfie, moving from tenth to sixth.
The top 10 girls' names were Olivia, Ruby, Emily, Grace, Jessica, Chloe, Sophie, Lily, Amelia and Evie.
Evie was the only new entry in the top 10, replacing Ella.
There were some distinct regional variations, in particular with the name Mohammed.
Overall, the choice was 16th favourite, but it was second in the West Midlands, third in London and fourth in Yorkshire and Humberside.
In contrast, in the south west of England, Mohammed came in at number 151.
There were also notable seasonal variations with Holly number 22 overall in 2008, but the most popular choice among girls born in December.
Looking back over the decade, Kian was the highest climbing boy's name between 1998 and 2008, while Jordan fell the furthest from 10 to 150.
Among baby girls, Lexi was the highest climber over the 10-year-period, while Rebecca saw the biggest decline.
The top three boys' names in Scotland were Jack, Lewis and Daniel, while for girls the favourites were Sophie, Emily and Olivia.
Welsh mothers like singer Charlotte Church prefer Ruby for their daughters
According to the Northern Ireland Statistics and Research Agency, the top three boys' choices there were Jack, Matthew and Daniel, and girls' were Katie, Sophie and Grace.
Ruby held on to top place in Wales, possibly influenced by the choice of Welsh singer Charlotte Church who chose the name for her daughter in September 2007.
The latest ONS figures came as a survey by parenting club Bounty.com suggested that teachers pigeonhole children as naughty or nice depending on their first name.
Callum and Chelsea were deemed most likely to misbehave, while Alexander and Elisabeth were most often thought to be model pupils.