Timo Nieminen (born October 6, 1981 in Helsinki) is a retired professional Finnish tennis player.
He reached his highest ATP Tour singles ranking of World No. 254 in July 2003. Nieminen primarily played on the Futures circuit and the Challenger circuit. He has been a member of the Finland Davis Cup team since 2002, posting a 2–12 record in singles and 0–1 record in doubles in 12 ties.
He is no relation to Jarkko Nieminen.
Tour singles titles - all levels (16)
| Legend (Singles) |
| Grand Slam (0) |
| Tennis Masters Cup (0) |
| ATP Masters Series (0) |
| ATP Tour (0) |
| Challengers (0) |
| Futures (16) |
| No. | Date | Tournament | Surface | Opponent in the final | Score |
| 1. | 2002 | Jūrmala | Clay | Andrei Cherkasov | 4–6, 6–4, 6–2 |
| 2. | 2003 | Savitaipale | Clay | Michail Elgin | 6–3, 6–4 |
| 3. | 2003 | Vierumäki | Hard | Mait Künnap | 6–3, 6–2 |
| 4. | 2003 | Gothenburg | Hard (i) | Robert Lindstedt | 6–2, 4–6, 6–1 |
| 5. | 2006 | Kraków | Clay | Julian Reister | 2–6, 6–3, 6–1 |
| 6. | 2007 | Sydney | Hard | Ti Chen | 7–5, 6–4 |
| 7. | 2008 | Oslo | Clay | Stian Boretti | 6–3, 6–4 |
| 8. | 2009 | Vierumäki | Clay | Juho Paukku | 7–5, 2–6, 6–4 |
| 9. | 2009 | Lidköping | Hard (i) | Frederik Nielsen | 6–2, 6–2 |
| 10. | 2010 | Alkmaar | Clay | Michal Schmid | 6–1, 6–3 |
| 11. | 2010 | Vilnius | Clay | Deniss Pavlovs | 7–5, 6–2 |
| 12. | 2010 | Leimen | Hard (i) | Holger Fischer | 6–3, 7–5 |
| 13. | 2011 | Båstad | Clay | Cătălin Gârd | 6–3, 6–7, 6–4 |
| 14. | 2011 | Vierumäki | Clay | Vladimir Ivanov | 6–3, 6–1 |
| 15. | 2011 | Isernhagen | Hard (i) | Peter Torebko | 6–2, 6–4 |
| 16. | 2012 | Båstad | Clay | Lucas Pouille | 2–6, 7–5, 6–2 |