Sellpy is a Swedish company founded in Stockholm in 2014. They help people sell used clothing and other items they no longer need. They handle the entire sales process from picking up the goods from sellers' homes, to photographing, selling and shipping.

The rapid purchase-to-discard ratio of fast fashion and piling up of clothing in landfills, often made from synthetic materials which do not decompose easily. When consumers throw away clothing in the garbage, not only does it waste money and resources, but it can take 200+ years for the materials to decompose in a landfill. During the decomposition process, textiles generate greenhouse methane gas and leach toxic chemicals and dyes into the groundwater and our soil. There is also the unmet potential of clothing which could be resold, and its lifetime extended- as opposed to manufacturing new clothing which requires more energy and water use, and is associated with more carbon emissions. Finally, there are lack of incentives for people to responsibly pass on/resell their unwanted clothing due to the associated costs- be that time or monetary (e.g. shipping).

Sellpy addresses these problems through providing an easy way to redirect unwanted clothing and thus divert it from landfills. It also provides a second-hand marketplace thus encouraging buying second hand and diverting ‘new new’ purchases, thus hopefully slowing down resource depletion.

As of 2021, Sellpy has said more than nine million garments have been sold in total on its platform.

Sellpy is majority-owned by H&M. In 2021, they announced an expansion into 20 new markets, taking its total span to 24. H&M has invested more than 20 million euros in Sellpy and owns around 70% of the company. Sellpy said that its collaboration with H&M gives it access to an H&M warehouse in Poland, as well as service around distribution, quality control of garments and order handling.