Thaddäus "Thaddy" Robl (22 October 1877 – 18 June 1910) was a German professional cyclist who was active between 1894 and 1910, initially in road racing, later predominantly in motor-paced racing. From 1895 to 1898 he obtained several podium finishes in long-distance road races, the most emblematic of which is his 3rd place in the 1898 Bordeaux - Paris.

In motor-paced racing he won five European titles (1901–1904, 1907) and the world championships in 1901 and 1902, he finished in third place in 1903.

After retiring from cycling he became passionate with flying the early planes. In a flight demonstration on 18 June 1910 in Szczecin (then German Empire) he fell from a height of about 75 meters. This was the first death of a civil pilot on the German ground. In 1947, a street in Munich was named after him.