Many populations of long-distance migrant shorebirds are declining rapidly. Since the 1970s, the Lesser Yellowlegs (Tringa flavipes) has experienced a pronounced reduction in abundance of ~63%. The potential causes of the species’ decline are complex and interrelated yet understanding the timing of migration and seasonal routes used by this species will aid in directing conservation planning to address potential threats. During 2018–2021, we tracked 118 adult Lesser Yellowlegs using GPS satellite tags deployed on birds from five breeding and two migratory stopover locations spanning the boreal forest of North America from Alaska to eastern Canada. Our objectives were to quantify migratory connectivity and identify key stopover and non-breeding locations. Individuals tagged in Alaska and central Canada followed similar southbound migratory routes through the Prairie Pothole Region of North America, whereas birds tagged in eastern Canada completed multi-day transoceanic flights covering distances of >4,000 km across the Atlantic between North and South America. Upon reaching their non-breeding locations, Lesser Yellowlegs populations overlapped, resulting in weak migratory connectivity. Lastly, freshwater and agricultural habitats of the Prairie Pothole region supported the highest proportion of Lesser Yellowlegs during southbound migration. Our findings suggest that while Lesser Yellowlegs travel long distances and traverse numerous political boundaries each year, the breeding population from which an individual originates likely has the greatest influence on which threats birds experience during migration. Further, the species’ dependence on wetlands in agricultural landscapes during migration may make them vulnerable to threats related to agricultural practices, such as pesticide exposure.