The Canadian population of Barn Swallow is best monitored by the Breeding Bird Survey, which samples much of the breeding range and has high precision for this species. The national trend shows a steady to slightly increasing trend throughout the 1970s, but then a steep drop in the 1980s and 1990s before tapering off to a more gradual decline ever since. The pattern has been fairly similar across most of Canada, with cumulative losses most serious (>90% since 1970) in Yukon and the Maritimes. The only notable exception is in the southern Prairies, where the population increased until the early 1980s, the subsequent decline was less severe than elsewhere in the country, and there has been a slight rebound since 2005, although even there the population is 27% below 1970 levels. The declines are corroborated by breeding bird atlases in Ontario, Quebec, and the Maritimes.

The goal for Barn Swallow is to increase the population to the level it was at in the early 1970s, based on the Breeding Bird Survey. Trend data show that Barn Swallow is currently below its goal range and continuing to decline. Analysis considering the historical population loss and recent trend suggests that it is unlikely that the goal can be met by 2050, so the interim target is to reach 50% of the goal by 2050. Achieving this target, and ultimately reaching the national goal for this species, will require deliberate conservation action.