Peter Dreher (1932 – 2020) was a German artist and academic teacher. Dreher became known for his series Tag um Tag guter Tag which he began in 1974, painting the same glass more than 5,000 times. He painted it more than 2,500 times at night and more than 2,500 times during the daytime, in a process similar to meditation. Dreher also created series of landscapes and interiors, flower pieces and skulls. Dreher was a lecturer of painting at the Academy of Fine Arts, Karlsruhe from 1965, and from 1968 a professor there. He retired from his position in 1997.