Sumitomo Chemical Co., Ltd. (住友化学株式会社, Sumitomo Kagaku Kabushiki-gaisha) is a major Japanese chemical company. The company is listed on the first sectionof the Tokyo Stock Exchange and is a constituent of the on the Nikkei 225 stock index. It's a member of the Sumitomo group and was founded in 1913 as a fertilizer manufacturing plant.