Olio is a mobile app that helps people in their community share items for free. The app aims to reduce household and food waste by connecting neighbors who have extra food or household items with others nearby who want to pick up those items. The food given away must be safe to eat and can be raw or cooked, sealed or open. Non-food items often listed on Olio include books, clothing, and furniture.

People who donate extra food can be individuals or businesses, such as grocery stores, restaurants, company cafeterias, and food photographers. Donations can happen once or regularly. For example, some supermarkets in the UK, including Tesco, the Midcounties Co-operative, Morrisons, Sainsbury's, and Iceland, have tested Olio as an "online food bank" to reduce food waste. In March 2022, Olio partnered with Pandamart in Singapore.

Olio was first launched in early 2015 by Tessa Clarke and Saasha Celestial-One. By October 2017, the company had raised $2.2 million in funding. In 2018, Olio completed a Series A funding round of $6 million, and in a later round called Series B, it raised $43 million. Investors include Accel, Octopus Ventures, and VNV Global. As of May 2023, the Olio app had about 7 million registered users.