Daniel Altmaier (born 12 September 1998) is a German tennis player.
Altmaier has a career high ATP singles ranking of world No. 210 achieved on 3 July 2017. He also has a career high ATP doubles ranking of No. 372 achieved on 26 June 2017.
Altmaier made his ATP main draw debut as a qualifier at the 2017 Geneva Open, defeating Alexander Ward and Petr Michnev in qualifying. He lost to Sam Querrey in the first round.
Altmaier won his first ATP tour-level match as a lucky loser at the 2017 Antalya Open when he beat Víctor Estrella Burgos. In the next round, he defeated wildcard Marsel İlhan to reach the quarterfinals, where he lost to Yūichi Sugita. Both of his victories were decided by a third set tie break.
ITF Future titles
|1.||26 June 2016||Havre, Belgium||Clay||Maxime Authom||6–2, 6–2|
|2.||24 July 2016||Knokke, Belgium||Clay||Casper Ruud||6–7(3–7), 6–1, 7–6(7–3)|
|3.||4 December 2016||Doha, Qatar||Hard||Jonny O'Mara||7–5, 6–3|
|4.||19 February 2017||Bellevue, Switzerland||Carpet (i)||Tim Pütz||7–5, 7–6(7–5)|
|5.||9 April 2017||Doha, Qatar||Hard||Antoine Escoffier||6–4, 6–3|
|1.||8 February 2015||Colombo, Sri Lanka||Clay||Tom Schönenberg|| José Checa Calvo
|6–7(6–8), 6–3, [11–9]|
|2.||18 September 2016||Damme, Belgium||Clay||Marvin Netuschil|| Oscar Otte
|3.||23 October 2016||Santa Margherita di Pula, Italy||Clay||Marvin Netuschil|| Claudio Fortuna
|4.||6 November 2016||Mishref, Kuwait||Hard||Fred Simonsson|| Sanjar Fayziev
|5.||20 November 2016||Mishref, Kuwait||Hard||Marcus Willis|| Roy de Valk
|6.||19 February 2017||Bellevue, Switzerland||Carpet (i)||Marvin Netuschil|| Maximilian Neuchrist
|7–5, 1–6, [11–9]|