Reiner was born Lucas Joseph Reiner in Los Angeles, California on August 17, 1960, the third child of actor, comedian, director and writer Carl Reiner and visual artist and performer Estelle (née Lebost) Reiner.

He attributes his interest in art to his mother; both studied with painter Martin Lubner. Between 1978 and 1986, Reiner attended Parsons School of Design and The New School for Social Research in New York, Otis Art Institute in Los Angeles, and Parsons School of Design Paris. He began exhibiting in group shows in New York (The Drawing Center, Grand Salon) and Los Angeles (Manny Silverman) in the early 1990s, before having his first solo exhibition of paintings at Bennett Roberts (1995, Los Angeles).

In subsequent years, he has exhibited individually at Roberts & Tilton and Carl Berg Projects in Los Angeles, Galerie Biedermann and Galerie Peter Bauemler in Germany, and Galeria Traghetto and Claudia Gian Ferrari Arte Contemporanea in Italy, and in group exhibitions at L.A. Louver, CSU Luckman Gallery, Edward Cella Art + Architecture, and Bridge Projects, among others.