Professor X is a mutant who possesses vast telepathic powers, and is among the most powerful telepaths in the Marvel Universe.
Professor X is able to perceive the thoughts of others or project his own thoughts within a radius of approximately 250 miles (402 km). With extreme effort, he can greatly extend the range of his telepathy. He can learn foreign languages by reading the language centers of the brain of someone adept, and alternately "teach" languages to others in the same manner; Xavier once trained a new group of mutants mentally, subjectively making them experience months of training together, while only hours passed in the real world.
Xavier's vast psionic powers enable him to manipulate the minds of others, warp perceptions to make himself seem invisible, project mental illusions, cause loss of particular memories, and induce pain or temporary mental and/or physical paralysis in others. Within close range, he can manipulate almost any number of minds for such simple feats. However, he can only take full possession of one other mind at a time, and must strictly be within that person's physical presence. He is one of the few telepaths skilled enough to communicate with animals and even share their perceptions. He has displayed telepathic prowess sufficient to confront Ego the Living Planet, while aided by Cadre K as well as confront and narrowly defeat Exodus.
He can cause the loss of specific memories or even total amnesia. He can also project powerful mental 'bolts,' enabling him to stun the mind of another person into unconsciousness or even cause death. These 'bolts' inflict damage only upon other minds, having a negligible effect on non-mental beings, if any. The manner in which Xavier's powers function indicates that his telepathy is physical in some way, as it can be enhanced by physical means (e.g., Cerebro) and can be disrupted by physical means (e.g., Magneto's alteration of the Earth's magnetic field).
Xavier can perceive the distinct mental presence/brain waves of other superhuman mutants within a small radius of himself. To detect mutants to a wider area beyond this radius, he must amplify his powers through Cerebro and subsequently Cerebra, computer devices of his own design which are sensitive to the psychic/physical energies produced by the mind.
Professor X can project his 'astral form' into a psychic 'dimension' known as the 'astral plane.' There, he can use his powers to create objects, control his surroundings, and even control and destroy the astral forms of others. He cannot project this form over long distances.
Uncanny X-Men writer Ed Brubaker has claimed that, after being de-powered by the Scarlet Witch, and then re-powered by the M'Kraan Crystal, Charles' telepathy is more powerful than was previously known. However, the extent of this enhancement is unknown.
Charles is a genius with multiple doctorates. He is a world-renowned geneticist, an expert in mutation, possesses considerable knowledge of life sciences, and is the inventor of Cerebro. He is the leading authority on genetics, mutation, and psionic powers, and possesses considerable expertise in other life sciences. He possesses a Ph.D. in genetics, biophysics, and psychology. He is highly talented in devising equipment for utilizing and enhancing psionic powers.
During his travels in Asia, Xavier learned martial arts, acquiring "refined combat skills" according to Magneto. When these skills are coordinated in tandem with his telepathic abilities, Xavier is a dangerous unarmed combatant, capable of sensing the intentions of others and countering them with superhuman efficiency. He also has extensive knowledge of pressure points.