Hans-Joachim Hartnick (born 12 January 1955) is a retired East German cyclist. He had his best achievements in the 100 km team time trial. In this discipline he won a silver medal at the 1980 Summer Olympics, a bronze medal at the world championships in 1974 and a gold medal at the world championships in 1979; his team finished in 10th place at the 1976 Summer Olympics.
Individually, he won the following races:
- DDR-Rundfahrt, 1974 and 1975
- Hill Climb Championship, 1975
- Korneuburg, 1975
- Peace Race, 1976
- Rund um Berlin, 1977
- Thüringen Rundfahrt der U23, 1979
- Tour de l'Yonne, 1981
He finished in second place in the Peace Race in 1975.