The agency will help plan a year of celebrations to champion the "power of reading and inspire children to dream big".
The brief includes delivering media relations throughout the year to raise awareness of the anniversary and drive sales of The Puffin Book of Big Dreams, which will be published in May.
The celebratory collection of more than 40 new stories will include authors and illustrators, as well as classic content that embodies the publisher's past, present and future.
It will also feature the "dreams of children" who have participated in the Puffin World of Stories programme – funded by Puffin and run by the National Literary Trust.
Francesca Dow, managing director of Penguin Random House Children's, said: "We want to reach still wider and new audiences through our creative brand partnerships in our 80th year – encouraging tech-heavy family households to engage with the power of stories – so we can continue to inspire children to dream big in 2020 and beyond."
Alongside the celebratory collection, Premier will support additional partnerships – among them a Puffin podcast hosted by author, comedian and YouTuber Humza Arshad; a nationwide events programme; and creative brand partnerships with MCM Comic Con and educational charity Into Film.
Alice Bruce, director of Premier's Entertainment division, said: "Like millions, we grew up with the magic of Puffin books and it's a huge privilege to play a part in the 80th celebrations. We'll be reminding readers young and old of the incredible stories Puffin has brought to the world and looking to the future to reveal what comes next."