Johan van Lom (or van Lomme, called Johan van Lom the Old) (before 1465 – 24 March 1538 or 1539) was a politician and philanthropist from Venlo, Netherlands.
He married Katharina (Katryn or Tryne), who was possibly of the house van Eijll before 1500, and then to Margaret van Vernich (Verningen, Vernych), widow of Herman Heesmans.
Other than his political career, he is noted as a philanthropist of religious institutions near Roermond and Venlo.
Possibly to one Catherine van Eijll, and definitely to Margaret van Vernich, widow of Herman Heesmans.
Molhuysen and Blok (1937) attribute all of his children to Catherine.