Disclosed herein is a new and distinct variety of Petunia plant named 'Sunpurple' having a decumbent growth habit and long stems. 'Sunpurple' has abundant branching, and great profusion of blooms, the whole plant remaining in bloom for a considerable period of time. The flowers are single and medium size, the petals having vivid reddish purple color. The bottom and the outside color of the corolla throat is deep reddish purple. The plant exhibits high resistance to heat, cold, rain and diseases.