Social innovations are grassroots processes aiming to achieve impacts beyond an individual level and towards a broader societal good. The environmental dimension of impacts refers to any direct change to the environment resulting from social innovation activities, products, or services, which are not addressed by pre-existing systems. In this paper, we determine the role of social innovation in addressing environmental impacts by analyzing a database of social innovation examples in European and circum-Mediterranean rural areas, compiled within the H2020 Project SIMRA. We conceptualize the overall aim of environmentally-focused social innovation initiatives as furthering the sustainable development of their territories. To address the environmental impacts of initiatives in a structured way, we use the Sustainable Development Goals (SDG) classification, to describe social innovation environmental impacts in relation to specific targets. We analyzed 238 initiatives from the SIMRA catalog and associated initiative websites to identify and classify their direct environmental impacts. Our results indicate that 68% of the cases have at least one direct environmental impact that aligns with a SDG target. The most common impacts are related to sustainable natural resource management (SDGs target 12.2), sustainable food production systems (2.4), and equal access to land (2.3). This SDG-based classification proved to be a useful analytical tool for categorizing internationally policy-relevant environmental impacts of social innovations.