Abstract: Here we present the first documented occurrence of a GPS-tagged Pallid Harrier (Circus macrourus) in the Slovak Republic, along with the summary of observations in this country in the last ten years (2012–2021), and underline the importance of GPS-GSM tagging in birds. The individual, a second calendar-year male, tagged with a solar GPS-GSM transmitter as pullus in the nest near Dobřichov, Czech Republic in 2020, migrated across the Slovak territory on May 8, 2021 and between September 2, and September 6, 2021. In the first case, it migrated from Austria across the westernmost part of Slovakia, reaching the Czech Republic in less than two hours. The individual occurred in Slovakia again during autumn migration on September 2, when it crossed the Slovak-Ukrainian border in Sobrance District, flew over the Východoslovenská nížina Lowland and on September 3, it continued along the Slovak-Hungarian border, mostly in Hungary. The bird re-entered Slovakia on September 4 (Levice District), moving westwards across southwestern Slovakia. It roosted in Šaľa District (the night of September 4–5) and in M.R. Štefánik Airport (Vrakuňa, Bratislava II District, the night of September 5–6). The observation and documentation of the bird took place in the area of M.R. Štefánik Airport on the morning of September 6, and represents one of only two records of this scarce migrant during the autumn migration in 2021 in Slovakia. The individual crossed the Slovak-Austrian border shortly after the observation and progressed with the migration.