Official relations were established in 1919, although contacts date back over 1000 years,[1] with frequent migrations in both directions, substantial cultural exchange, extensive trade, and, in the modern era, mutual assistance in times of need.

[4] In the early 13th century Duke Henry the Bearded invited further Walloon immigrants to the area of Oława and Wierzbno to the south of Wrocław.

[8] During his Grand Tour in 1624, Polish Prince and future King Władysław IV Vasa visited the workshop of Flemish painter Peter Paul Rubens.

[13] Polish princess Jadwiga Lubomirska, wife of Eugène, 8th Prince of Ligne, received Poles at her residences in Brussels and Belœil.

Unique instances include Captain Józef Godebski, who became a lecturer and developed a geometry textbook that was mandatory in all military schools in Belgium, and Feliks Jastrzębski, who established a piano factory, winning a medal at an exhibition in 1841 and later becoming a supplier to Belgian kings.

[22] Migration of Poles to Belgium continued also later in the 19th and early 20th centuries, including of writer Maria Dąbrowska née Szumska, who first met her future husband, activist Marian Dąbrowski in Brussels.

Elisabeth of Bavaria, Queen of the Belgians initiated assistance to Poland during the Polish–Soviet War of 1919–1920, first by organizing fundraising to buy medicines and bandages.

[24] Belgium also supported Polish war invalids, and donated medicines for typhoid patients and food for children who had lost their homes.

Belgians, alongside Poles and other nationals, were also among the prisoners of the particularly notorious Nazi German camps in Żabikowo, Miłoszyce, Świecko and Słońsk.

[34] General Stanisław Maczek became an honorary citizen of almost every Flemish town he liberated, and multiple squares and streets were named after either him or his soldiers.