Tondeleyo is a name which was invented for a character in a play first produced in
London in 1923 called
White Cargo, written by
Leon Gordon. The play was then made into a famous film with actress
Hedy Lamarr playing the character Tondelayo in 1942.
Though the play was based on a novel called
Hell's Playground by
Ida Vera Simonton, the character is not called Tondeleyo in the novel and so the name was probably invented by
Leon Gordon. The character is a half-European half-African woman and the story is set in West
Africa around 1910.
Gordon seems to have just made up the name from whole cloth as it doesn't really resemble most West African names that I've seen. In the movie the character played by
Hedy Lamarr is said to be "half Egyptian and half Arab", and the setting is so vague that a lot of viewers didn't even realize it was supposed to be
Africa, and so it's often remembered as having been set in Polynesia -- which is why you will see a few references that wrongly list Tondelayo as a Polynesian name.
The spelling was Tondeleyo in the play, but most references to the film spell it Tondelayo. The variations with -a at the end come simply from parents assimilating the name they heard to what seemed like a more normal "feminine" ending.