Name: Mr. Curator
First Appearance: Batman (vol. 1) #172 (June 1965): "Attack of the Invisible Knights!"
Number of Appearances: 1
Employer: Gotham City Museum
As odd as it may seem, the unnamed curator in this story - the curator of Gotham City Museum - was actually called "Mr. Curator" by his employees. Certainly this wasn't his real name, but it was apparently a title his people routinely used when addressing him.
Museum guard Thomas Jenkins (who doubles as a guide) addressed the curator as "Mr. Curator" in panel 5 on page 3. Later, in panel 2 on page 4, another museum employee addresses his boss as "Mr. Curator."