The trio of artists will be joined by Fall Out Boy, Rizzle Kicks and Icona Pop at the ceremony which will recognise the best music of the last 12 months, with winners to be crowned in the Best British Song, Best British Solo Artist and Best British Group categories.
Grimshaw said: ''The Teen Awards are one of the jewels in the crown in Radio 1's year and it's an honour to host it again. Always loud, hectic and chaotic, Rita is gonna need some earplugs. I hope after this we can present everything together!''
In addition to celebrity winners, three youngsters will also win a Teen Hero Award after they were nominated by Radio 1 listeners for their good deeds and chosen by a panel of judges.
BBC Radio 1 Commissioning Editor Piers Bradford said: ''The Radio 1 Teen Hero Awards are a great opportunity to shine a light on some amazing teens. We receive hundreds and hundreds of inspiring and inspirational stories during the nomination process, and it is almost an impossible task to decide who is most deserving of the award. One thing you can guarantee is that the winners will be incredible - and so is the line-up!''
Tickets will be available from 9am on Saturday 12 October.
BBC Radio 1 Teen Awards full line-up:
Fall Out Boy
There's already an Oscars buzz surrounding this movie.