Alex the Cat is Felix's near look-alike cousin from Australia. Alex resembles Felix in every way except one: he is completely white. He disguises himself as Felix by painting himself black in order to steal Felix's girl.

In the Van Beuren shorts distributed from 1929 to 1930, Felix spoke and sang in a high-pitched, childlike voice provided by then-21-year-old Walter Tetley, who was a popular radio actor in the 1930s, but later best known as the voice of Sherman on The Rocky and Bullwinkle Show's Mister Peabody segments.

When television was in the experimental stages in 1928, the very first image to ever be seen was a toy Felix the Cat mounted to a revolving phonograph turntable. It remained on screen for hours while engineers used it as a test pattern.

Felix co-starred with Betty Boop in the Betty Boop and Felix comic strip, which ran from November 19, 1984 to January 31, 1988. Unlike most other incarnations of the famous cat, Felix never spoke in this strip. His ideas and opinions are conveyed to the reader in thought balloons.

Felix is the oldest high school mascot in the state of Indiana, chosen in 1926 after a Logansport Berries player brought his plush Felix to a basketball game. When the team came from behind and won that night, Felix became the mascot of all the Logansport High School sports teams.

Created during the silent film era by Pat Sullivan and Otto Messmer, Felix was a smash hit with audiences and held the title of world's most popular cartoon character for a few years until Walt Disney introduced the world to a certain mouse. Unfortunately for Felix, the Pat Sullivan Studio was behind the curve in adding sound to their cartoons, and lost much of the market to other, more technologically advanced studios like Fleischer and Disney.

For Felix the Cat's 100th anniversary, Universal Pictures dubbed 9 November "Felix the Cat Day" and released new merchandise, including a Pop! figure, Skechers brand shoes, clocks, a PEZ dispenser, shirts, bags, pillows, and pomade.