Harry Kellar (1849 - 1922) was an American magician who presented large stage shows during the late 1800s and early 1900s. Kellar was arguably the predecessor of Harry Houdini and the successor of Robert Heller. He was often referred to as the Dean of American Magicians and performed extensively on five continents. One of his most memorable stage illusions was the levitation of a girl advertised as the Levitation of Princess Karnack.

His real name was Heinrich Keller, born to German immigrants in Erie, Pennsylvania and constantly experimented in adolescence with games of chicken and with the production of various chemical concoctions. On one occasion, young Heinrich reportedly blew a hole in the floor of his employer's drugstore and rather than confront parental wrath, he stowed away on a train and continued life as a vagabond. It was on the road that he encountered the Fakir of Ava, who inspired his direction into conjuring. Kellar was probably one of the most meticulous performers of his day, focusing on both his presentation and on his array of magic tricks. Aside from The Kellar Rope Tie, another highlight was The Vanishing Birdcage, an effect which he originally purchased from its inventor, Buatier De Kolta during the late 1870s, for the incredible reported sum of $750.

Each evening, the lamp would be returned to its original owner at a specific time, which was approaching. A bell chimed the current hours of the day as Kellar loaded a pistol and aimed it towards the lamp. At the last chime the pistol was fired. The lamp simply melted away to nothing and vanished, the cloth falling to the stage. Kellar's automaton "Psycho", which was a version of the John Algernon Clark idea used in Maskelyne's original card-playing robot, was a popular sensation wherever it played. Perhaps one of Kellar's least known advancements in magic would be his modification to the levitation illusion, which as was later purchased by Harry Blackstone, Sr. from the Kellar estate. Blackstone successfully used the illusion for many years.

Harry Kellar retired in 1908, and handed over the mantle of America's Greatest Magician to Howard Thurston. In 1918, Harry Houdini arranged for Kellar to perform once more for a show benefitting families of the men who died when the troop transport vessel Antilles was sunk by a German U-boat. Never one for understatement, Houdini arranged for Kellar to be carried off stage in triumph as six thousand spectators sang Auld Lang Syne. This would end up being Harry Kellar's final public performance.

• Harry Houdini, born as Ehrich Weisz, claimed that he adopted the first name 'Harry' in homage of Harry Kellar. (The 'Houdini' surname derives from Robert-Houdin).

• Kellar spent several years employed as an agent and business manager to the Davenport Brothers.