We collected survey data based on representative samples from Finnish academics (N = 2,492), local politicians (N = 510), and media professionals (N = 695). We found that 64% of politicians, 58% of media professionals, and 30% of academics had experienced work-related online harassment. Among university staff, perceived social support from colleagues was negatively associated with self-censorship, and perceived social support from the closest supervisor had similar association among media professionals and politicians. Additionally, the frequency and severity of the harassment, as well as the target’s public visibility and female gender as predicted, along with other sociodemographic characteristics, were associated with self-censorship in response to online harassment. The results suggest that characteristics of the harassment and the target’s work environment influence the silencing effect of work-related online harassment and that perceived social support at work constitutes an important resource in dealing with harassment and its potential consequences.