Depending on who you want to believe, Braine-le-Comte railway station (FBC) in… Braine-le-Comte (‘s-Gravenbrakel) in Walloon Brabant is Belgium‘s oldest or second oldest railway station building still in use.
The competitor is Tienen (Tirlemont) in Limburg. Both buildings were inaugurated in 1841.
The Wikipedia pages differ. The Dutch version states 1840 for Tienen. The French and English versions say 1841. The French page for Braine-le-Comte says FBC is the oldest.
I saw Braine’s assistant station master and a shunter on Wednesday. Unsurprisingly, they were adamant FBC is Belgium’s oldest.
The building was wrapped. But you can find old photos on Gares Belges.