The line, which ranges from £3.99 - £24.99, features socks, hats, sweatshirts, sweatpants, a t-shirt dress, and waist bag.
"The merch features the official logos of the 18-year-old singer-songwriter in oversized silhouettes and all the clothing has been made from materials sourced in a more sustainable way," the company states on its website.
None of the collection uses animal materials such as leather or fur and is mainly blends of polyester and cotton.
According to The Independent, Emily Bjorkheim, H&M's Head of Design Divided, said: "Billie Eilish is obviously an inspiring artist, but also someone a lot of people around the world admire for her personal style and empowering way of expressing her values.
"We want to enable her fans to step into her world and feel empowered to freely express their style as well."
Last year, H&M launched its Conscious Exclusive range, which featured cowboy boots made with vegan pineapple leather and a 'silk' dress created from orange peels.
"For this collection, we explored the beauty in nature, which shows in the prints, as well as the flowy silhouettes, the striking color palette and the attention to detail," Ann-Sofie Johansson, Creative Advisor at H&M, said.
"We're thrilled to introduce new plant-based sustainable materials to create high-performing, beautiful and fashionable pieces that are statement-making yet so easy to wear."
You can shop the Billie Eilish Merch Collection here