Namesakes
Danish Kings and Queens:
4 kings
King Valdemar I the Great 1157-1182 
King Valdemar II the Victorious 1202-1241
King Valdemar III 1326-1330
King Valdemar IV Atterdag 1340-1375
Olympic Medalists:
2 bronze, 1 gold
(gold) Eric Lemming (a.k.a. Valdemar) 1908; 1912 javelin throw - freestyle; javelin throw
(bronze) Kurt Lundquist (a.k.a. Valdemar) 1948 4x400 m relay
(bronze) Voitto Hellsten (a.k.a. Valdemar) 1956 400 m
Other Royalty:
2 princes
Felix of Denmark (a.k.a. Valdemar) 2002-2023 Denmark
Christian, Crown Prince of Denmark (a.k.a. Valdemar) 2005- Denmark
Swedish Kings and Queens:
1 king
King Valdemar 1250-1275