ATP Buenos Aires 02/10 17:30 25 [95] Jaume Munar v Thiago Monteiro [92] 3-6,3-6
ATP Cordoba 02/04 19:30 25 [71] Corentin Moutet v Thiago Monteiro [89] 6-4,6-3
Challenger Punta del Este 02/02 21:30 29 [77] Marco Cecchinato v Thiago Monteiro [86] 6-7,7-6,5-7
Challenger Punta del Este 02/02 00:35 28 [388] Felipe M R Alves v Thiago Monteiro [86] 3-6,3-6
Challenger Punta del Este 02/01 00:00 27 [328] Guilherme Clezar v Thiago Monteiro [86] 4-6,1-6
Challenger Punta del Este 01/30 22:45 26 [228] Francisco Cerundolo v Thiago Monteiro [86] 5-7,4-6
Challenger Punta del Este 01/30 00:00 25 Mariano Kestelboim v Thiago Monteiro 4-6,4-6
Australian Open 01/21 10:00 23 [19] John Isner v Thiago Monteiro [86] 6-7,7-6,7-6,7-6
ATP Auckland 01/15 03:00 26 [86] Thiago Monteiro v Benoit Paire [24] 6-4,4-6,3-6
ATP Auckland 01/13 02:30 25 [52] Cameron Norrie v Thiago Monteiro [87] 6-7,2-6
ATP Auckland 01/11 22:00 164 [87] Thiago Monteiro v Leonardo Mayer [88] 7-6,4-6,6-1
ATP Auckland 01/11 00:10 64 Thiago Monteiro v Ajeet Rai 6-4,6-2
ATP Doha 01/05 12:30 164 [82] Gregoire Barrere v Thiago Monteiro [89] 6-4,6-4
ATP Doha 01/04 09:10 64 Rashed Nawaf v Thiago Monteiro 2-6,0-6
Challenger Montevideo 11/06 14:00 25 [318] Guilherme Clezar v Thiago Monteiro [88] 7-6,6-7,6-3
Challenger Guayaquil 10/30 16:00 25 [311] Thiago Seyboth Wild v Thiago Monteiro [89] 7-6,7-6
Challenger Lima 10/27 18:00 29 [97] Thiago Monteiro v Federico Coria [131] 6-2,6-7,6-4
Challenger Lima 10/26 19:45 28 [161] Juan P Varillas v Thiago Monteiro [97] 4-6,2-6
Challenger Lima 10/25 21:15 27 [97] Thiago Monteiro v Juan Pablo Ficovich [260] 7-5,6-3
Challenger Lima 10/24 21:55 26 [97] Thiago Monteiro v Yannick Hanfmann [187] 1-6,6-3,7-5
Challenger Lima 10/22 16:45 25 [97] Thiago Monteiro v Martin Cuevas [443] 6-3,7-6
Challenger Santo Domingo 10/12 21:00 28 [238] Juan P Varillas v Thiago Monteiro [106] 6-4,6-2
Challenger Santo Domingo 10/11 21:00 27 [106] Thiago Monteiro v Alejandro Tabilo [224] 6-3,6-2
Challenger Santo Domingo 10/10 19:00 26 [106] Thiago Monteiro v Oscar Jose Gutierrez [390] 6-3,7-5
Challenger Santo Domingo 10/09 00:20 25 Thiago Monteiro v Victor Estrella Burgos 6-2,6-2
Challenger Campinas 10/02 23:40 25 [385] Maxime Hamou v Thiago Monteiro [105] 7-5,4-6,6-1
Challenger Buenos Aires 09/28 14:00 28 [108] Thiago Monteiro v Sumit Nagal [161] 0-6,1-6
Challenger Buenos Aires 09/27 15:30 27 [215] Andrea Collarini v Thiago Monteiro [108] 6-3,1-6,5-7
Challenger Buenos Aires 09/26 14:00 26 [356] Christian Lindell v Thiago Monteiro [108] 6-7,6-7
Challenger Buenos Aires 09/25 14:00 25 Thiago A Tirante v Thiago Monteiro 1-6,2-6

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.