Olivia Rodrigo has teamed up with Casetify on a new collection of phone cases.

The 'drivers license' singer creatively directed and handpicked all the designs for a Hardened Heart collection for the lifestyle brand and had a great time working on the project.

She said: “It was really cool to be able to help create this collection with Casetify that reflects my vision and keeps sustainability at the forefront of each design."

Casetify were delighted to have Olivia on board.

Wes Ng, cofounder and chief executive officer of Casetify, said: “Olivia used her voice to inspire people across the globe to express themselves, and that’s what our mission is at Casetify. From her ability to connect with young people to her desire to support sustainability, we are excited to partner with her.”

The 18-year-old pop star will appear in a social campaign for the range, as well as their first out-of-home campaign.

Their partnership will last for a year and will also include another collection, as well as an in-person event.

Cases in the Hardened Heart collection will be sustainable and made using the brand's Re/Casetify technology, which turns old used phone cases into brand new ones. There will also be designs on a range of Impact and Ultra Impact cases, which are made from 65% recycled material and offer up to 10-foot drop protection.

Products in the range - which also include a mirror case and an Ultra Compostable Case, which is 100% biodegradable - will retail between $45 and $75 and will go on sale through the company's website and app from 15 December, though a wait list has already been opened.