| Joachim Büchner | |
| Birth Date: | 8 April 1905 |
| Birth Place: | Altenburg, German Empire |
| Death Date: | 22 February 1978 (aged 72) |
| Death Place: | Leverkusen, West Germany |
| Height: | 1.76m (05.77feet) |
| Weight: | 74kg (163lb) |
| Sport: | Running |
| Club: | Viktoria Magdeburg VfB Leipzig |
| Olympics: | 1928, 1932 |
| Show-Medals: | yes |
Joachim "Jochen" Büchner (8 April 1905 – 22 February 1978) was a German sprint runner who won a bronze medal in the 400 m event at the 1928 Olympics. He failed to reach the 400 m final at the next Olympics, and finished in fourth place with the German 4 × 400 m relay team. He won three national titles in the 400 m in 1927–1929 and finished second in 1925, 1931 and 1932. In 1928 he became the first German athlete to run 400 m within 48 seconds.
Büchner was a graphic designer and advertising consultant. After retiring from competitions, he worked at ASV Köln, first as athletics coach (1947–1950), then treasurer (1962–1969) and later as president (1969–1977). Until his death in 1978 he was a member of the Association of Former Track and Field Athletes of West Germany. Büchner's daughter Christa (born 1931) became a pentathlete.