During the last half hour of the movie, when the four X-men are leaving in the jet, Logan says, "You actually go outside in these things?" to which Cyclops replies, "Well, what would you prefer, yellow spandex?" In the comics, Logan's outfit is yellow spandex.

In the beginning when the 20th century fox logo is fading the 'x' stays on just a bit longer.

After Toad kicks Storm down the elevator shaft, but she rises back up, he says angrily, "Don't you people ever die?" This is in reference to the fact that nearly every member of the X-Men has died at least once in the comics/cartoons, but have come back to life.

In the scene where Logan meets Professor Xavier for the first time, the girl who forgets her bag and then goes through the closed door is Kitty Pryde, aka Shadowcat.

Stan Lee, creator of X-Men (you may recognise him if you've seen Mallrats), has a cameo on the beach scene as a hot dog vendor.

In the scene where Rogue is in class and she gets that ice rose from Bobby, the girl sitting next to her is Jubilee, another X-men character.

At the end when Logan is leaving the mansion, you can hear on the news that they found Gyrich and asumed he was mauled by a bear. Submitted by Piemanmoo

The trucker who drives Rogue to Northern Alberta is the actor who does Beast's voice from the X-Men cartoon series.

In the shot where security guards in the Statue of Liberty find the body of another guard (actually Mystique's body) with Wolverine's claw marks in the chest, the security guard crouched by the body is in fact X-Men's screenwriter - David Hayter.

Although this is not a mistake, I just want to point it out. When Toad (Ray Park) is fighting Storm (Halle Berry) at the statue of liberty he kicks her into an elevator shaft. He then proceeds to remove a bar that was holding the doors of the elevator open and he does a spin move that is a definitely supposed to look exactly like the spin he did with his lightsabre in Star Wars: Episode I. For those of you who don't know, Park played Darth Maul in that film. [Cross reference with Sleepy Hollow, also starring Ray Park as one of the swordsman actors - he does a similar move in that too. Clearly a trademark]

On the X-Men 2 DVD, the filmmakers mentioned this. If you think about it, in X-Men (only really relevant to the first film, given Nightcrawler and Deathstrike turn up in the second one), all of the X-Men are beautiful and handsome actors and actresses, but all the villians are weird-looking, ugly beasts, or freaks of nature. Magneto's the one exception.

Wolverine's jacket is black with three yellow stripes on the arm. Those are Wolverine's same colors as in the comics.

This comes from one of the set designers, and is referenced in Wizard: the Guide to Comics; If you look closely, the designs of the sets often have "hidden" X's and O's incorporated into their designs.

Natalie Portman was offered the role of Jubilee. When she turned the part down, the character was written out of the script.

In the scene by the Statue of Liberty where Toad squashes a security guard, that security guard is actually X-Men's executive producer - Tom DeSanto.

Neither Ian McKellen nor Patrick Stewart knew how to play chess.

The man who plays the guard in the plastic prison cell is David Hayter, the man who wrote the screenplay and, to most gamers, the voice of Solid Snake in the Metal Gear Solid game series.

In the cartoon series, Wolverine and Rogue can't stand each other.