Hannu Vaahtoranta was a Finnish freestyle swimmer who was active during the 1960s. Vaahtoranta won bronze in the 100 metres freestyle at the Nordic Championships in 1961 and 1963, along with setting a Nordic record in the 400 metres medley at the 1962 European Championships. At the 1964 Tokyo Olympics he was part of the Finnish team that finished in tenth place in the 4 × 200 metres freestyle relay in addition to swimming in the 100 metres freestyle and 400 metres medley races. Vaahtoranta then worked as a coach for 15 years, becoming the training and coaching manager at the Finnish Swimming Association from 1977 to 1980. He worked with the Swedish team to develop high-level training camps and coached the Finnish team at the 1980 Moskva Olympics.