Tuomas Kristian Seppänen (born 16 May 1986) is a Finnish athlete specialising in the hammer throw. He was born in Pori, and represented his country at three consecutive European Championships, his best outing being the twelfth place in 2014.
His personal best in the event is 76.20 metres set in 2016 in Halle.
| Representing | ||||||
|---|---|---|---|---|---|---|
| 2005 | European Junior Championships | Kaunas, Lithuania | 7th | Hammer throw (6 kg) | 70.95 m | |
| 2007 | European U23 Championships | Debrecen, Hungary | 9th | Hammer throw | 67.67 m | |
| 2010 | European Championships | Barcelona, Spain | 15th (q) | Hammer throw | 72.94 m | |
| 2011 | Universiade | Shenzhen, China | 7th | Hammer throw | 71.04 m | |
| 2012 | European Championships | Helsinki, Finland | 20th (q) | Hammer throw | 71.15 m | |
| 2013 | Universiade | Kazan, Russia | 7th | Hammer throw | 73.89 m | |
| 2014 | European Championships | Zürich, Switzerland | 12th | Hammer throw | 73.70 m | |
| 2015 | World Championships | Beijing, China | 10th | Hammer throw | 73.18 m | |
| 2016 | European Championships | Amsterdam, Netherlands | 23rd (q) | Hammer throw | 69.76 m | |
| 2022 | World Championships | Eugene, United States | 23rd (q) | Hammer throw | 72.81 m | |
| European Championships | Munich, Germany | 16th (q) | Hammer throw | 71.24 m | ||
| 2024 | European Championships | Rome, Italy | 20th (q) | Hammer throw | 72.85 m | |