There should be no surprise that Negima is rich in references and comparisons to the famous series and there's a good reason it's known as the Japanese Harry Potter. Whether it be intentional or coincidence, we've compiled a full list of Harry Potter references found in the entire Negima series.
This one is obvious, but both series revolve around magic and the world of wizards/mages.
After the first Harry Potter film was shot, the actor who played Headmaster Dumbledore, Richard Harris, passed away and was replaced for the second movie onward. By a freaky coincidence, the English voice actor, Randy Tallman, who played the headmaster of Mahora, Konoemon Konoe, had also passed away after the first season of Negima and was replaced for the future season.
The French logo of the Negima! anime has a striking resemblance to Harry Potter's logo
Negi himself bears a similar appearance and heritage to the main character, Harry Potter, fit with the round glasses, both being about 10 at the start of the series, and the English heritage. Negi's concept art looks even more like the popular star, even featuring an unused owl cage.
When asked about his age, Negi revealed he was 9 3/4, an intentional nod to the boarding platform from Harry Potter. This particular number was only said in the English dub version of the first anime series.
Some of the music from Negima's live action series is very similar to the songs in Harry Potter. For example, one of the songs from the first episode of the live actions sounds quite similar to the main theme of Harry Potter. (Skip to 3:14 in first video)
During the fourth chapter, Negi offers to take Asuna up on his staff, making a comment about her not making Quidditch jokes. This was not in the original Japanese version, but added in the English release. Quidditch, of course, is a popular sports involving brooms in Harry Potter.
Though it's unsure whether it was intentional or not, both series feature a Love Potion. In Harry Potter, the Weasley twins sell these potions and have been banned from Hogwarts. In Negima, love potions are outright illegal, but that doesn't stop Negi from concocting one. Both only last temporarily.
Ch. 28 - When traveling on the train to Kyoto, Haruna attempts to give Yuuna chocolate, but is greeted with a frog instead. This is a clever nod to Harry Potter, where Harry opens a box of candy on the train to Hogwarts and finds it is an animated chocolate frog.
Though it's debatable whether it's intentional or not, Negima briefly features two mystical creatures, the three-headed dog and Hippogriff, that were both found in the Harry Potter books.