Vivica Bandler (5 February 1917 – 30 July 2004) was a Finnish theater director. She was a close friend and part-time lover of Tove Jansson, the two met in 1946 and would collaborate on two theater plays and a television show, where Bandler acted as a director of Jansson's scripts.
The secret relationship between Vivica Bandler and Tove Jansson inspired the characters Thingumy and Bob. The connection is even more clear in the original Swedish names Tofslan and Vifslan, which where nicknames they would sometimes call each other.
The book Moominsummer Madness was dedicated to Vivica Bandler, and likely inspired by their work together in theater.