ATP Budapest Qual 04/22 10:45 - [185] Hubert Hurkacz v Thiago Monteiro [126] 2-6,7-5,6-3
ATP Budapest Qual 04/21 12:00 26 [187] Stefano Napolitano v Thiago Monteiro [126] 1-6,4-6
Challenger Mexico City 04/12 23:35 26 [314] Juan Ignacio Londero v Thiago Monteiro [125] 6-4,6-1
Challenger Mexico City 04/11 01:45 25 [382] Manuel Sanchez v Thiago Monteiro [125] 3-6,3-6
Davis Cup 04/07 23:30 28 Daniel Elahi Galan v Thiago Monteiro 6-3,6-3
Davis Cup 04/06 20:00 28 [290] Santiago Giraldo v Thiago Monteiro [125] 1-6,2-6
ATP Miami Qual 03/19 20:00 44 [175] Thanasi Kokkinakis v Thiago Monteiro [125] 6-2,6-3
Challenger Santiago 03/06 14:00 25 Thiago Monteiro v Gian Marco Moroni 2-6,3-6
ATP Sao Paulo 02/28 02:05 25 Guilherme Clezar v Thiago Monteiro 6-3,1-6,7-5
ATP Rio De Janeiro 02/20 19:30 25 Thiago Monteiro v Pablo Cuevas 7-6,6-7,3-6
ATP Buenos Aires 02/13 18:20 25 Thiago Monteiro v Fernando Verdasco 2-6,5-7
ATP Quito 02/10 20:50 28 Thiago Monteiro v Albert Ramos-Vinolas 4-6,7-6,4-6
ATP Quito 02/09 21:30 27 Thiago Monteiro v Gael Monfils 6-4,2-6,6-4
ATP Quito 02/08 19:30 26 Thiago Monteiro v Alessandro Giannessi 7-6,4-6,7-5
ATP Quito 02/06 17:00 25 Horacio Zeballos v Thiago Monteiro 4-6,6-7
Davis Cup 02/03 21:30 27 Jose Hernandez-Fernandez v Thiago Monteiro 6-4,7-6
Davis Cup 02/02 22:30 27 Roberto Cid Subervi v Thiago Monteiro 7-6,5-7,2-6
Australian Open Qual 01/10 06:40 44 Thiago Monteiro v Lorenzo Sonego 5-7,3-6
ATP Pune 01/03 15:30 26 Thiago Monteiro v Kevin Anderson Retired
ATP Pune 01/02 13:55 25 Thiago Monteiro v Ruben Bemelmans 6-7,6-3,7-6
ATP Pune Qual 12/31 10:15 - Thiago Monteiro v Prajnesh Gunneswaran 7-5,7-5
ATP Pune Qual 12/30 11:30 26 Thiago Monteiro v N.Sriram Balaji 3-6,6-3,7-5
Challenger Rio De Janeiro 11/25 16:35 28 [128] Thiago Monteiro v Carlos Berlocq [125] 2-6,6-7
Challenger Rio De Janeiro 11/24 21:00 27 [101] Rogerio Dutra Silva v Thiago Monteiro [128] 6-7,5-7
Challenger Rio De Janeiro 11/23 17:30 26 Roberto C Baena v Thiago Monteiro 6-7,3-6
Challenger Rio De Janeiro 11/23 12:00 25 Andre Ghem v Thiago Monteiro 2-6,1-6
Challenger Santiago 2 11/17 22:00 28 [129] Thiago Monteiro v Nicolas Jarry [118] 2-6,2-6
Challenger Santiago 2 11/16 17:00 27 [129] Thiago Monteiro v Carlos Berlocq [121] 6-3,0-6,6-4
Challenger Santiago 2 11/15 16:00 26 Thiago Monteiro v Roberto Carballes Baena 5-7,7-6,6-2
Challenger Santiago 2 11/13 16:00 25 [129] Thiago Monteiro v Javier Marti [254] 5-7,6-4,6-3

Thiago Moura Monteiro (Brazilian Portuguese: [tʃiˈaɡu mõˈtejɾu]; born 31 May 1994) is a Brazilian professional tennis player.

Monteiro has a career-high ATP singles ranking of world No. 61 achieved on 17 October 2022. He also has a career-high ATP doubles ranking of No. 144, achieved on 31 January 2022. He is currently the No. 2 Brazilian tennis player.

On the ITF Junior Circuit, Monteiro peaked in the rankings at No. 2 on 2 February 2012, with his biggest junior singles title being the Grade A, Copa Gerdau in Porto Alegre, Brazil, in 2011.

In his first ATP match, as a wildcard ranked world No. 338 in the ATP 500 Rio de Janeiro in February 2016, Monteiro upset No. 9 Jo-Wilfried Tsonga in the first round. In the second round, Monteiro lost to eventual champion Pablo Cuevas. In his next tournament, the ATP 250 São Paulo, Monteiro won two matches (against former World No. 9 Nicolás Almagro, and Daniel Muñoz de la Nava), losing again to eventual champion Cuevas in the quarterfinals.

On May 8, 2016, Monteiro won his first ATP Challenger title in Aix-en-Provence, France. He defeated Carlos Berlocq in the final.