Jonáš Forejtek
Jonáš Forejtek is a Czech professional tennis player. He has achieved a career-high ATP ranking of 565 in singles and 364 in doubles. He also has reached a career-high ITF juniors ranking of 1 in the world.
On 25 January 2019, Forejtek and his partner Dalibor Svrčina won the 2019 Australian boys' doubles title, beating Emilio Nava and Cannon Kingsley in the finals. In the 2019 US Open boys’ singles Forejtek defeated Emilio Nava in the Final 6–7, 6–0,6–2.
Junior Grand Slam finals
Singles
Doubles
Challenger and Futures finals
Singles: 1 (0–1)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Czech Republic F9, Valašské Meziříčí | Futures | Hard |  Karol Drzewiecki | 3–6, 4–6 |
Doubles: 1 (0–1)
| Result | W–L | Date | Tournament | Tier | Surface | Partner | Opponents | Score |
| Loss | 0–1 | Czech Republic F7, Liberec | Futures | Carpet |  Jan Mertl | Marek Gengel Petr Nouza | 6–2, 3–6, |