El punto material, masa puntual o partícula es una idealización física en la que se considera el cuerpo en estudio como si fuese puntual, es decir carente de dimensiones, cualquiera que sea su tamaño, dependiendo tan solo del contexto del problema a tratar. El paradigma de esta idealización es considerar cuerpos de gran tamaño, como los planetas, como si fuesen masas puntuales, a los efectos de aplicar las leyes de la Gravitación Universal. Desde un punto de vista cinemático, el único tipo de movimiento admisible para un punto material es el movimiento de traslación, ya que al carecer de dimensiones no puede poseer rotaciones intrínsecas o movimiento de rotación. En la física existen otras abstracciones de sistemas en estudio como los sistemas de partículas y los sólidos rígidos, entre otros.

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A point particle (ideal particle or point-like particle, often spelled pointlike particle) is an idealization of particles heavily used in physics. Its defining feature is that it lacks spatial extension: being zero-dimensional, it does not take up space. A point particle is an appropriate representation of any object whose size, shape, and structure is irrelevant in a given context. For example, from far enough away, an object of any shape will look and behave as a point-like object. In the theory of gravity, physicists often discuss a point mass, meaning a point particle with a nonzero mass and no other properties or structure. Likewise, in electromagnetism, physicists discuss a point charge, a point particle with a nonzero charge. Sometimes, due to specific combinations of properties, extended objects behave as point-like even in their immediate vicinity. For example, spherical objects interacting in 3-dimensional space whose interactions are described by the inverse square law behave in such a way as if all their matter were concentrated in their centers of mass. In Newtonian gravitation and classical electromagnetism, for example, the respective fields outside of a spherical object are identical to those of a point particle of equal charge/mass located at the center of the sphere. In quantum mechanics, the concept of a point particle is complicated by the Heisenberg uncertainty principle, because even an elementary particle, with no internal structure, occupies a nonzero volume. For example, the atomic orbit of an electron in the hydrogen atom occupies a volume of ~10−30 m3. There is nevertheless a distinction between elementary particles such as electrons or quarks, which have no known internal structure, versus composite particles such as protons, which do have internal structure: A proton is made of three quarks. Elementary particles are sometimes called "point particles", but this is in a different sense than discussed above.

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