| Harald Theissen | |
| Birth Date: | 1959 3, df=yes |
| Birth Place: | Troisdorf West Germany |
| Plays: | Right-handed |
| Careerprizemoney: | $36,019 |
| Singlesrecord: | 6–11 |
| Singlestitles: | 0 |
| Highestsinglesranking: | No. 214 (3 January 1983) |
| Australianopenresult: | 2R (1982) |
| Doublesrecord: | 4–16 |
| Doublestitles: | 0 |
| Highestdoublesranking: | No. 178 (7 July 1986) |
| Australianopendoublesresult: | 1R (1982) |
Harald Theissen (born 23 March 1959) is a former professional tennis player from Germany.[1]
Theissen competed in the 1982 Australian Open and won a five set match over Lloyd Bourne in the opening round of the singles draw, before losing in the second round to Mike Bauer.[2] In the men's doubles he and partner Damir Keretić lost in the first round to Peter Johnston and John McCurdy.[2]