ATP Miami 03/21 20:30 14 [166] Dmitry Popko v Thiago Monteiro [116] 6-4,4-6,6-4
Davis Cup 03/05 19:45 45 [114] Thiago Monteiro v Alexander Zverev [3] 1-6,5-7
Davis Cup 03/04 21:00 45 [114] Thiago Monteiro v Jan-Lennard Struff [60] 6-3,1-6,6-3
ATP Santiago 02/25 14:30 27 [78] Sebastian Baez v Thiago Monteiro [107] 7-5,3-6,6-4
ATP Santiago 02/23 22:00 26 [107] Thiago Monteiro v Federico Delbonis [37] 3-6,6-4,6-1
ATP Santiago 02/22 01:20 25 [143] Nicolas Jarry v Thiago Monteiro [107] 6-7,4-6
ATP Rio De Janeiro 02/18 17:30 26 [6] Matteo Berrettini v Thiago Monteiro [106] 6-4,6-7,6-3
ATP Rio De Janeiro 02/15 22:00 25 [72] Sebastian Baez v Thiago Monteiro [106] 6-1,4-6,4-6
ATP Buenos Aires 02/09 19:20 26 [104] Thiago Monteiro v Fernando Verdasco [201] 6-2,3-6,5-7
ATP Buenos Aires 02/08 18:25 25 [32] Albert Ramos-Vinolas v Thiago Monteiro [104] 3-6,3-6
ATP Cordoba 01/31 17:30 25 [61] Pedro Martinez v Thiago Monteiro [92] 4-6,6-4,7-6
Australian Open 01/18 02:55 23 [56] Benoit Paire v Thiago Monteiro [79] 6-4,3-6,7-5,2-6,7-5
ATP Adelaide 2 01/13 03:45 27 [83] Thiago Monteiro v Corentin Moutet [115] 4-6,4-6
ATP Adelaide 2 01/12 08:30 26 [19] Gael Monfils v Thiago Monteiro [83] Retired
ATP Adelaide 2 01/11 08:50 25 [83] Thiago Monteiro v Yoshihito Nishioka [99] 1-6,6-3,6-4
ATP Adelaide 2 01/10 06:00 19 [85] Steve Johnson v Thiago Monteiro [89] 7-6,6-4
ATP Adelaide 2 01/09 04:45 26 [458] Harry Bourchier v Thiago Monteiro [89] 6-7,1-6
ATP Adelaide 01/05 04:50 26 [89] Thiago Monteiro v Marin Cilic [30] 4-6,6-7
ATP Adelaide 01/03 01:55 25 [89] Thiago Monteiro v Daniel Altmaier [84] 6-2,3-6,7-6
Challenger Campinas 11/21 19:25 29 [94] Thiago Monteiro v Sebastian Baez [111] 1-6,4-6
Challenger Campinas 11/20 19:00 28 [129] Tomas Martin Etcheverry v Thiago Monteiro [94] 6-1,2-6,3-6
Challenger Campinas 11/19 20:30 27 [94] Thiago Monteiro v Timofey Skatov [259] 6-7,6-3,7-6
Challenger Campinas 11/17 23:00 26 [94] Thiago Monteiro v Juan Pablo Varillas [127] Retired
Challenger Campinas 11/16 13:00 25 [94] Thiago Monteiro v Johan Nikles [360] 6-2,6-1
Challenger Montevideo 11/12 20:30 27 [159] Juan Ignacio Londero v Thiago Monteiro [95] 6-3,7-6
Challenger Montevideo 11/11 17:00 26 [273] Juan P Ficovich v Thiago Monteiro [95] 1-6,2-6
Challenger Montevideo 11/09 17:50 25 [190] Renzo Olivo v Thiago Monteiro [95] 7-6,2-6,6-7
Challenger Buenos Aires 10/24 16:00 29 [92] Thiago Monteiro v Sebastian Baez [124] 4-6,0-6
Challenger Buenos Aires 10/23 16:55 28 [92] Thiago Monteiro v Francisco Cerundolo [116] 6-1,2-6,6-3
Challenger Buenos Aires 10/22 15:00 27 [92] Thiago Monteiro v Tomas Martin Etcheverry [138] 6-4,3-6,7-5

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.