| Jan Adriaensens | |
| Fullname: | Cesar Jan Adriaensens |
| Birth Date: | 1932 6, df=yes |
| Birth Place: | Willebroek, Belgium |
| Discipline: | Road |
| Role: | Rider |
| Proyears1: | 1952–1953 |
| Proteam1: | Libertas |
| Proyears2: | 1953 |
| Proteam2: | Rochet–Dunlop |
| Proyears3: | 1954 |
| Proteam3: | Libertas–Huret |
| Proteam4: | Plume–Vainqueur |
| Proteam5: | Dossche Sport |
| Proteam6: | l'Express |
| Proteam7: | Rochet–Dunlop |
| Proteam8: | Alpa |
| Proyears9: | 1955 |
| Proteam9: | Libertas–Huret |
| Proteam10: | Terrot–Hutchinson |
| Proteam11: | Plume–Vainqueur |
| Proyears12: | 1956 |
| Proteam12: | Mercier–BP–Hutchinson |
| Proyears13: | 1957 |
| Proteam13: | Carpano–Coppi |
| Proyears14: | 1958 |
| Proteam14: | Carpano |
| Proyears15: | 1959 |
| Proteam15: | Elvé–Peugeot |
| Proteam16: | Peugeot–BP–Dunlop |
| Proyears17: | 1960 |
| Proteam17: | Philco |
| Proyears18: | 1961 |
| Proteam18: | Groene Leeuw–SAS–Sinalco |
| Majorwins: | Four Days of Dunkirk (1956) |
Jan (Cesar Jan) Adriaensens (6 June 1932 - 2 October 2018)[1]) was a Belgian road bicycle racer. He finished twice on the podium of the Tour de France, with a third place in 1956 and in 1960. In both these years, he wore the yellow jersey as the leader of the general classification.