Portugal was represented at the Junior Eurovision Song Contest 2017 with the song "Youtuber", written by João Cabrita and Mariana Andrade, and performed by Mariana Venâncio. The Portuguese participating broadcaster, (RTP), organised a national final in order to select its performer for the contest, after having previously selected the song internally.
=== === The singer who performed the Portuguese entry for the Junior Eurovision Song Contest 2017 was selected through the singing competition ("Juniors of Portugal"). 5 artists participated in a televised production named where the winner was determined by a 50/50 combination of both public vote and the votes of a jury invited by the production. The artists all performed a JESC song and a cover song. The competing song, titled "Youtuber", written by João Cabrita and Mariana Andrade, was revealed on 29 September 2017. The jury members of were:
The final, hosted by Jorge Gabriel and Sónia Araújo, took place on 5 October 2017 in RTP Studios in Porto. Filipa Ferreira and Mariana Venâncio was tied at 9 points each but since Mariana Venâncio received the most votes from the televoting she was declared the winner.
During the opening ceremony and the running order draw which both took place on 20 November 2017, Portugal was drawn to perform in position 6 on 26 November 2017, following and preceding .