Voting in the first ever Welsh Youth Parliament election will begin on Monday.
A total of 40 seats are up for grabs with 480 young people standing as candidates.
Voters must register to take part, and 13,000 11-18 year olds have already signed up.
Many schools will be arranging their own polling days, with the results expected to be announced early in December. Voting closes on 25 November.
The Welsh Youth Parliament was established by the National Assembly for Wales after its predecessor - Funky Dragon - was axed in 2014 following a loss of funding from the Welsh Government.
Elin Jones, the assembly's presiding officer, said: "This is happening after years of planning and consultation with more than 5,000 young people across Wales and is a key part of how the national assembly will involve the next generation in our work.
"I would urge anyone who is eligible and hasn't registered to vote to visit the Welsh Youth Parliament website, to find out who is standing for election in their area and how they intend to represent you."
Those who register to take part will be able to vote for candidates standing in their constituency.
Once elected Welsh Youth Parliament Members will serve a two-year term.
Another 20 young people will be selected to join the parliament by associated organisations including the Urdd, Girlguiding Cymru and Learning Disability Wales.
The election, which will take place electronically, opens at 10:00 GMT and closes at 17:00 on 25 November.
Registration for voters, who must be aged between 11 and 18, is open on the youth parliament website until 16 November.