Although Common Yellowthroats (Geothlypis trichas) are Nearctic-Neotropical migrants that are common breeders across the United States and Canada, very little has been published about the migration and stopover ecology of this species. We used spring migration banding records of Common Yellowthroats from 1992–2001 on Appledore Island, Maine, to investigate potential sexual and age-related differences in migration timing and stopover ecology of this species. Arrival dates of males were significantly earlier than arrival dates of females during spring, with mean male arrival five days earlier than female arrival. Also, after-second-year (ASY) birds arrived significantly earlier than second-year (SY) birds within each sex. Males also were significantly heavier than females upon arrival on Appledore. During spring migration, 5.0% of males and 4.2% of females were recaptured at least one day after initial capture, resulting in a mean stopover length of approximately three days for both sexes. We found no significant difference in the mean minimum stopover length nor the rate of mass change between the sexes based on recaptured individuals. Furthermore, we found no significant differences in stopover ecology between age groups within either sex. Both sexes significantly increased mass during stopover, both as calculated from recaptured individuals and as estimated by regression of condition (mass × 100/wing chord) over time. Results of this study confirmed differential migration among Common Yellowthroats, which is consistent with previous studies of passerine migration ecology. Lack of differences in stopover ecology between the sexes or between age groups suggests that earlier arrival of males than females and of ASY birds than SY birds may be due to an earlier onset of migration rather than increased migration speed.