Youngsters on average spent 91p per week on soft drinks, according to a survey from the Office for National Statistics (ONS) carried out between 2015 and 2017.
That compared with 77p spent on games, toys and hobbies, 57p on computer consoles and software and 54p on confectionery.
The figures are likely to prompt concern about childhood obesity amid concerns that youngsters are consuming too many unhealthy snacks and soft drinks.
More than half (56%) of children bought at least one soft drink in a typical fortnightly period and older children were more likely to do so.
Meanwhile, 48% spent money on confectionery such as chocolate and sweets over two weeks.
On average, children between seven and 15 spent £12.40 a week, with seven-year-olds typically spending £7.40 and fifteen-year-old spending £25.
The biggest outlays were on clothes and shoes, followed by school dinners, and then soft drinks.
The British Soft Drinks Association said manufacturers had voluntarily agreed in 2016 not to advertise any drinks high in sugar to under-16s across all media channels.
Director general Gavin Partington said: “As has been the case for a number of years, no and low calorie beverages account for the largest category in the UK soft drinks sector which is why sugar intake from soft drinks has reduced by almost 19% since 2013.”
Last month, Public Health England said children should be limited to two snacks of no more than 100 calories per day.
It warned that on average, children consume at least three unhealthy snacks and sugary drinks, with around a third having four or more – meaning children can easily have three times more sugar than is recommended.