| Challenger Gran Canaria | 02/28 15:10 | 25 | [296] Nicolas Alvarez Varona v Andrej Martin [128] | 1-6,1-6 | |
| Challenger Pau | 02/20 09:00 | 14 | [332] Yannick Maden v Nicolas Alvarez Varona [308] | 7-6,6-2 | |
| Challenger Forli | 02/14 11:05 | 19 | [347] Benjamin Hassan v Nicolas Alvarez Varona [308] | Retired | |
| Challenger Forli | 02/13 16:15 | 14 | [342] Matteo Viola v Nicolas Alvarez Varona [307] | 7-5,4-6,3-6 | |
| Challenger Rio De Janeiro | 12/19 19:00 | 29 | [319] Kaichi Uchida v Nicolas Alvarez Varona [371] | 3-6,6-3,7-6 | |
| Challenger Rio De Janeiro | 12/18 21:20 | 28 | [371] Nicolas Alvarez Varona v Nicolas Kicker [233] | 6-2,7-5 | |
| Challenger Rio De Janeiro | 12/17 18:00 | 27 | Nicolas Alvarez Varona v Roy Smith | 6-4,6-4 | |
| Challenger Rio De Janeiro | 12/15 15:30 | 26 | [343] Luciano Darderi v Nicolas Alvarez Varona [371] | 3-6,1-6 | |
| Challenger Rio De Janeiro | 12/13 17:20 | 25 | [337] Facundo D Acosta v Nicolas Alvarez Varona [371] | 3-6,6-4,3-6 | |
| Challenger Florianopolis | 12/06 15:40 | 25 | [98] Pablo Cuevas v Nicolas Alvarez Varona [365] | 7-6,6-2 | |
| Challenger Sao Paulo | 12/02 15:30 | 26 | [443] Luciano Darderi v Nicolas Alvarez Varona [357] | 6-4,6-1 | |
| Challenger Sao Paulo | 11/29 16:55 | 25 | [357] Nicolas Alvarez Varona v Nicolas Kicker [229] | 7-5,6-3 | |
| Challenger Brazília | 11/25 16:15 | 26 | [132] Thiago Seyboth Wild v Nicolas Alvarez Varona [361] | Retired | |
| Challenger Brazília | 11/23 15:50 | 25 | [454] Bogdan Bobrov v Nicolas Alvarez Varona [361] | 3-6,6-7 | |
| Challenger Campinas | 11/18 14:00 | 26 | [377] Nicolas Alvarez Varona v Santiago F R Taverna [336] | 6-7,7-6,5-7 | |
| Challenger Campinas | 11/16 15:50 | 25 | [287] Orlando Luz v Nicolas Alvarez Varona [377] | 3-6,4-6 | |
| Challenger Campinas | 11/15 13:30 | 19 | [446] Bogdan Bobrov v Nicolas Alvarez Varona [377] | 5-7,2-6 | |
| Challenger Campinas | 11/14 16:00 | 26 | [382] Nicolas Alvarez Varona v Genaro Alberto Olivieri [348] | 6-3,3-6,7-6 | |
| Challenger Montevideo | 11/08 19:05 | 19 | Nicolas Alvarez Varona v Francisco Comesana | 4-6,1-6 | |
| Challenger Montevideo | 11/07 15:00 | 14 | [403] Nicolas Alvarez Varona v Rafael Matos [76] | 6-2,6-2 | |
| Challenger Guayaquil | 11/04 19:40 | 26 | [131] Tomas Martin Etcheverry v Nicolas Alvarez Varona [403] | 6-4,3-6,7-6 | |
| Challenger Guayaquil | 11/02 22:00 | 25 | [403] Nicolas Alvarez Varona v Diego Hidalgo [175] | 2-6,6-4,6-3 | |
| Challenger Guayaquil | 11/01 16:00 | 19 | [403] Nicolas Alvarez Varona v Alejandro Gonzalez [444] | 4-6,6-7 | |
| Challenger Guayaquil | 10/31 16:00 | 14 | Nicolas Alvarez Varona v Francisco Castro | 6-0,6-0 | |
| Challenger Losinj | 10/19 12:00 | 25 | [404] Nicolas Alvarez Varona v Nerman Fatic [369] | 5-7,2-6 | |
| Challenger Losinj | 10/18 08:00 | 19 | [404] Nicolas Alvarez Varona v Fabien Reboul [121] | 6-4,6-4 | |
| Challenger Losinj | 10/17 08:00 | 14 | [441] Nicolas Alvarez Varona v Ivan Sabanov [95] | 6-2,6-2 | |
| Challenger Alicante | 10/12 09:45 | 25 | [174] N.Sriram Balaji v Nicolas Alvarez Varona [441] | 5-7,6-4,6-4 | |
| Challenger Barcelona | 10/08 09:00 | 27 | [112] Hugo Gaston v Nicolas Alvarez Varona [441] | 6-2,6-1 | |
| Challenger Barcelona | 10/07 09:00 | 26 | [190] Filip Horansky v Nicolas Alvarez Varona [441] | 4-6,3-6 |
Nicolás Álvarez Varona (born 18 May 2001) is a Spanish tennis player.
Álvarez Varona has a career high ATP singles ranking of World No. 219 achieved on 17 October 2022. He also has a career high ATP doubles ranking of World No. 288 achieved on 3 April 2023.
Álvarez Varona made his ATP main draw debut at the 2022 Barcelona Open Banc Sabadell after qualifying for the singles main draw, defeating Philipp Kohlschreiber and wildcard Max Alcalá Gurri before losing to Brandon Nakashima.
Ranked No. 927, at the 2024 Barcelona Open Banc Sabadell he entered the qualifying competition with a wildcard.