Alwin Josef Wagner (born 11 August 1950 in Melsungen, Hessen) is a West German discus thrower and weight lifter, who was affiliated with University Sportclub Mainz (USC Mainz).
He finished sixth at the 1984 Summer Olympics. In Germany he is also well known for winning five national championships in a row in the years 1981-1985.
His personal best throw was 67.80 metres, achieved in July 1987 in Melsungen. This result ranks him sixth among German discus throwers, behind Jürgen Schult, Lars Riedel, Wolfgang Schmidt, Armin Lemme and Hein-Direck Neu. While competing, he was 1.96 meters tall and weighed 130 kg.