Employees aged 22 to 29-years-old had an average gross annual pay of £20,900 in 2015.
This compared with an average salary in the UK for all workers of £27,600, according to data from The Office for National Statistics.
Workers aged 18 to 21-years-old had an average salary of just £10,200.
The low figure for these workers can be explained in part by them being based on hourly earnings excluding overtime.
Full-time female employees aged 22-29 were paid slightly more than male employees last year, the statistics show.
Though the figures show that men earn more than women among all employees aged above 29-years-old.
View the full slideshow of statistics from the ONS, below.