Information is characterized as the reduction of uncertainty and by a change in the state of a receiving organism. Thus, organisms can acquire information about their environment that reduces uncertainty and increases their likelihood of choosing a best-matching strategy. We define the ecology of information as the study of how organisms acquire and use information in decision-making and its significance for populations, communities, landscapes and ecosystems. As a whole, it encompasses the reception and processing of information, decision-making, and the ecological consequences of making informed decisions. The first two stages constitute the domains of, e.g. sensory ecology and behavioral ecology. The exploration of the consequences of information use at larger spatial and temporal scales in ecology has lagged behind these other disciplines. In our overview we characterize information, discuss statistical decision theory as a quantitative framework to analyze information and decision-making, and discuss potential ecological ramifications. Rather than attempt a cursory review of the enormity of the scope of information we highlight information use in development, breeding habitat selection, and interceptive eavesdropping on alarm calls. Through these topics we discuss specific examples of ecological information use and the emerging ecological consequences. We emphasize recurring themes: information is collected from multiple sources, over varying temporal and spatial scales, and in many cases links heterospecifics to one another. We conclude by breaking from specific ecological contexts to explore implications of information as a central organizing principle, including: information webs, information as a component of the niche concept, and information as an ecosystem process. With information having such an enormous reach in ecology we further cast a spotlight on the potential harmful effects of anthropogenic noise and info-disruption.