The following is a list of the characters from the Ice Age films, mentioned by a name either presented in the films or in any other official material. Each character includes a summary when possible, the voice actor or actors associated with the character, and a description of the character along with any aliases, spouses and the character's species.

Manfred "Manny" is a woolly mammoth. His personality is shown to be aloof, grumpy, sarcastic and standoffish, but is otherwise loving and courageous. In the first film, while passing through the icy cave, the herd discovers cave paintings of Manny with his wife and son, who were killed by humans; this is a very sentimental moment for Manny, since he failed to protect them. Manny finds love with Ellie in Ice Age: The Meltdown. Because of the death of his family, in Ice Age: Dawn of the Dinosaurs, he is anxious when Ellie is pregnant.

At the end of the film, he becomes the proud father of a baby daughter named Peaches. In Ice Age: Continental Drift, he gets into an argument with his teenage daughter before being pulled away in by the drift with Diego, Sid and Granny. He and the team later encounter a group of pirates led by Captain Gutt. When the team escaped they destroy the ship and take Shira with them. This enrages the Captain who hunts them down. Later on, he is almost manipulated by sirens.

A running gag for Manny, shown in four of the five films, is that if a certain character were to refer to him as fat, he would often deny it, saying that "his fur is what makes him look big" and that "it's poofy".

Sidney "Sid" The Sloth is a ground sloth who is dull-witted, talkative, friendly, carefree, naive, accident-prone, patient and funny with a caring nature, and is voiced with a lateral lisp. Little is known from Sid's life other than that Sid once lived in a tree with other sloths that always wanted to leave Sid behind when the migration occurred, using several different ways to leave him behind. What is clear is that Sid's mother always told him that "bad news is just good news in disguise" before abandoning him for good.

He accidentally starts a fire in the first film and learns how to do it properly towards the end. He also shows this skill in the second film, where he is worshiped by a tribe of "mini-sloths" who call him "The Fire King" and try to sacrifice him. In the third film, he adopts a trio of baby T-Rexes, and is forcibly taken to the underground dinosaur land by their mother, requiring the others to come and save him.

In the fourth film, it is revealed that his full name is Sidney, though this name was also used in a deleted scene of the first film. When he, Diego and Manny are on the ice and are forced up by a water spout, they see a rainbow in the bright blue sky as he told them that "there is a rainbow at the end of every corner."

Sid was built along the form typical of ground sloths, short, brushy tail, clawed hands and feet, a long thin neck, ovular head with bulbous eye on both sides and a pair of buckteeth. Sid's right front tooth was slightly bigger than the left, similar to his right eye, which was also somewhat bigger than the left, both eyes of which were pale green. Sid's pelt was dirty and tan, and became brown when the fungus it carried dried out, Sid attributing the state of his pelt to his vegetarian diet, which he said led to a younger-looking pelt.