Thomas de Keyser was a Dutch portrait painter and a dealer in Belgium bluestone and stone mason. He was the most in-demand portrait painter in the Netherlands until the 1630s, when Rembrandt eclipsed him in popularity. Rembrandt was influenced by his work, and many of de Keyser's paintings were later falsely attributed to Rembrandt.

Hendrick de Keyser was a Dutch sculptor, merchant in Belgium bluestone, and architect who was instrumental in establishing a late Renaissance form of Mannerism changing into Baroque. Most of his works appeared in Amsterdam, some elsewhere in the Dutch Republic. He was the father of Pieter and Thomas de Keyser and Willem, and the uncle of Huybert de Keyser, who became his apprentices and all involved in building, decoration and architecture.