Ruffs can be found in a variety of open wetland habitats, including wet grasslands, marshlands, floodplains, sewage farms, and the edges of lakes, ponds, and estuaries. During migration, they frequent exposed muddy shores, agricultural fields, and short-grass pastures. Breeding occurs in tundra and Arctic wetlands.

Spotting Ruffs often involves observing their foraging behavior, where they probe in soft mud or pick items from the surface. Males are particularly conspicuous during the breeding season due to their elaborate and variable ruffs and head tufts, performing impressive displays at communal lek sites. Outside the breeding season, they are more subtly plumaged and often found in large, mixed-species wader flocks. Their calls are generally quiet, including soft 'tu-wit' notes or low grunts at leks.

Ruffs are primarily observed during their breeding season (May-July) in Arctic regions and during spring (March-May) and autumn (August-October) migration periods across their vast migratory routes. They are active during daylight hours, especially when foraging.