A foam insert for a rain gutter for a residential dwelling is provided. The foam insert prevents debris such as leaves, pine needles, gravel, and dirt from entering the rain gutter and permits water to pass through the foam and into the gutter. The foam insert has a channel in the outer side to receive the inwardly projecting lip of a gutter when the foam insert is placed into the gutter. As the foam inserts are installed in the gutter, the lip of the gutter is positioned within the channel. The foam is flexible, which permits the foam insert to be bent and maneuvered into position within the gutter. The foam inserts are formed with a pore size of 14 ppi or below. The foam inserts are inexpensive and may be quickly and easily installed or removed from the gutter by a single individual.