| Honorific-Prefix: | His Excellency |
| Koos Verdam | |
| Office: | Extraordinary Member of the Council of State |
| Term Start: | 1 March 1980 |
| Term End: | 1 February 1985 |
| Vicepresident: | Marinus Ruppert (1980) Willem Scholten (1980–1985) |
| Office1: | Queen's Commissioner of Utrecht |
| Term Start1: | 16 March 1970 |
| Term End1: | 1 February 1980 |
| Monarch1: | Juliana |
| Predecessor1: | Constant van Lynden van Sandenburg |
| Successor1: | Pieter van Dijke |
| Office2: | Member of the Senate |
| Term Start2: | 23 May 1967 |
| Term End2: | 16 March 1970 |
| Parliamentarygroup2: | Anti-Revolutionary Party |
| Term Start3: | 5 September 1966 |
| Term End3: | 5 April 1967 |
| Primeminister3: | Jo Cals (1966) Jelle Zijlstra (1966–1967) |
| Predecessor3: | Ivo Samkalden (Ad interim) |
| Successor3: | Henk Beernink |
| Birthname: | Pieter Jacobus Verdam |
| Birth Date: | 1915 1, df=y |
| Birth Place: | Amsterdam, Netherlands |
| Death Place: | Bilthoven, Netherlands |
| Nationality: | Dutch |
| Party: | Christian Democratic Appeal (from 1980) |
| Otherparty: | Anti-Revolutionary Party (until 1980) |
| Children: | Louwrens Verdam (1947–2006) Tjeerd Jan Verdam (1948–2013) 5 other children |
| Alma Mater: | Vrije Universiteit Amsterdam (Bachelor of Laws, Master of Laws, Doctor of Philosophy) |
| Occupation: | Politician · Jurist · Researcher · Academic administrator · Professor |
Pieter Jacobus "Koos" Verdam (15 January 1915 – 11 March 1998) was a Dutch politician of the defunct Anti-Revolutionary Party (ARP) now merged into the Christian Democratic Appeal (CDA).
The reformed Verdam was a professor for Roman law and international civil law at the Vrije Universiteit Amsterdam and from 1959 to 1960 its Rector Magnificus. From 1966 to 1967 he was the Minister of the Interior and Kingdom Relations in the Cabinet Zijlstra. In 1970 he became the Queen's Commissioner in Utrecht.
| Honours | ||||
| Ribbon bar | Honour | Country | Date | Comment |
|---|---|---|---|---|
| Knight of the Order of the Netherlands Lion | Netherlands | 3 June 1963 | ||
| Grand Officer of the Order of Orange-Nassau | Netherlands | 1 February 1980 | Elevated from Commander (27 April 1967) | |