Among Canadians aged 15 to 64, Internet access reached near-saturation levels in 2016, but its diffusion into the senior population was far less extensive. This study uses four cycles of the General Social Survey (2007, 2010, 2013 and 2016) to describe changes in Canadian seniors’ rates of Internet use, and examines the sociodemographic factors associated with such use. The findings suggest that age is the primary determinant of Internet use among seniors, but that differences in educational attainment and other demographic characteristics are also important. From 2007 to 2016, Internet use doubled from 32% to 68% among Canadians aged 65 and older. During this time, the absolute gap in the prevalence of Internet use between seniors and Canadians aged 45 to 54 declined from 49 to 28 percentage points. Within the senior population, Internet use progressively declined at older ages. Current age differences in Internet use likely correspond with the comparatively limited exposure of Canadian seniors to the Internet via their social networks, as well as differences in educational attainment and other characteristics correlated with Internet use. This suggests that the slow diffusion of Internet use in the senior population was rooted in historical circumstances more so than reflecting the aging process. Given the comparatively high rates of Internet use among middle-aged Canadians (aged 45 to 54) and younger seniors, it is anticipated that age gaps in Internet use will continue to decrease.