In order to see the dedication in Naomi's book, Arthur moves a pop-up moon over a Manhattan skyline scene. This is a tribute to the line "If you get caught between the moon and New York City," in Christopher Cross' "Arthur (1981)'s Theme" song.
Ricky Gervais turned down the lead role. He told the press, "I said 'no' straight-away. Why would I mess with a perfect comedy? They know people don't watch films that have the wrong font - it's got an '80s font".
When Arthur is talking to Susan's father in the Johnson Tower, and they put on the safety glasses, Burt's ear hook goes behind the ear and then on top of the ear and then back behind the ear.
Near the end of the movie, outside Naomi's apartment, Arthur states "My mum's dead." It was his Nanny, Hobson, that passed away, but she was more of a mother than Vivienne ever was, and Naomi would know that. (This is also parallel to the original film, in which Arthur tells a drunk "My father died" after the passing of Hobson. Arthur's actual father was still alive and well in the film.)