A rice cultivar designated Roy J is disclosed. The invention relates to the seeds of rice cultivar Roy J, to the plants of rice cultivar Roy J, to plant parts of rice cultivar Roy J, and to methods for producing a rice plant produced by crossing rice cultivar Roy J with itself or with another rice variety. The invention also relates to methods for producing a rice plant containing in its genetic material one or more transgenes and to the transgenic rice plants and plant parts produced by those methods. This invention also relates to rice cultivars, or breeding cultivars, and plant parts derived from rice cultivar Roy J, to methods for producing other rice cultivars, lines or plant parts derived from rice cultivar Roy J, and to the rice plants, varieties, and their parts derived from use of those methods. The invention further relates to hybrid rice seeds, plants, and plant parts produced by crossing rice cultivar Roy J with another rice cultivar.
