| Jacques Grandjean | |
| Birth Date: | 1 February 1954 |
| Singlesrecord: | 0–5 (ATP Tour & Davis Cup) |
| Highestsinglesranking: | No. 289 (3 Jan 1983) |
| Doublesrecord: | 1–1 (Davis Cup) |
| Highestdoublesranking: | No. 480 (3 Jan 1983) |
Jacques Grandjean (born 1 February 1954) is a Belgian former professional tennis player.[1]
Grandjean was a Davis Cup representative for Belgium and debuted in a 1982 tie against Israel in Eupen, losing his singles rubber in five sets to Shahar Perkiss. In 1983 he featured in further ties against Poland and West Germany. He reached a best singles world ranking of 289 and took a set off Johan Kriek (world no. 16) at the 1983 Brussels Indoor, one of his two Grand Prix circuit main draw appearances.[2] He won a national championship in doubles in 1985.[3]