Do-it-yourself biology (DIY biology, DIY bio) is a biotechnological social movement in which individuals, communities, and small organizations study biology and life science using the same methods as traditional research institutions.

DIY biology is primarily undertaken by individuals with limited research training from academia or corporations, who then mentor and oversee other DIY biologists with little or no formal training. This may be done as a hobby, as a not-for-profit endeavor for community learning and open-science innovation, or for profit, to start a business.