The best source of information on the population status of Great Crested Flycatcher is the Breeding Bird Survey (BBS). Its reliability is considered high because it samples the breeding range well and has high precision. The national BBS trend shows a slight increase in the late 1970s and late 1980s, then a gradual decline until around 2010, followed by a largely stable trend approximately one-third below 1970s levels. The declines have been greatest in central Ontario and Quebec and into the northern limits of the breeding range in the lower boreal forest. In the rest of the Canadian range, trends have also been slightly negative, but with cumulative losses of only 10 to 20%. 

The goal for Great Crested Flycatcher 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 Great Crested Flycatcher is currently below its goal range, but it has shown a stable trend over the past decade. Analysis of recent trends and potential growth rates suggests that Great Crested Flycatcher could reach its population goal by 2050 with the support of conservation action.