| Challenger - Liberec | 08/02 09:10 | 25 | Nicolas Alvarez Varona v Daniel Siniakov | 6-4,6-3 | |
| Challenger - Segovia | 07/25 17:10 | 25 | [264] Nicolas Alvarez Varona v Antoine Bellier [194] | 7-5,5-7,1-6 | |
| Challenger - Pozoblanco | 07/19 21:25 | 25 | [270] Nicolas Alvarez Varona v Vasek Pospisil [139] | 3-6,3-6 | |
| Challenger Iasi | 07/12 08:00 | 25 | [268] Nicolas Alvarez Varona v Pablo Andujar [105] | 4-6,4-6 | |
| ITF M25 Getxo | 07/05 17:15 | 25 | Nicolas Alvarez Varona v Alvaro Lopez San Martin | 6-7,1-6 | |
| Challenger Málaga | 06/30 17:00 | 26 | James McCabe v Nicolas Alvarez Varona | 6-4,6-1 | |
| Challenger Málaga | 06/27 14:25 | 25 | [270] Nicolas Alvarez Varona v Ernesto Escobedo [130] | 7-6,6-3 | |
| Challenger Forli | 05/29 08:00 | 14 | [272] Nicolas Alvarez Varona v Oscar Jose Gutierrez [416] | 2-6,6-7 | |
| Challenger Shymkent | 05/18 04:00 | 26 | [351] Nicholas D Ionel v Nicolas Alvarez Varona [274] | 6-2,4-6,6-2 | |
| Challenger Shymkent | 05/16 07:10 | 25 | Dragos Nicolae Madaras v Nicolas Alvarez Varona | 4-6,0-6 | |
| Challenger Shymkent | 05/11 07:00 | 26 | [338] Ulises Blanch v Nicolas Alvarez Varona [276] | 7-5,6-7,7-6 | |
| Challenger Shymkent | 05/09 09:05 | 25 | Aleksandre Metreveli v Nicolas Alvarez Varona | 3-6,1-6 | |
| Challenger Aix en Provence | 05/01 10:45 | 14 | Nicolas Alvarez Varona v Gabriel Debru | 5-7,3-6 | |
| ATP Barcelona | 04/18 11:10 | 24 | [285] Nicolas Alvarez Varona v Brandon Nakashima [81] | 6-7,3-6 | |
| ATP Barcelona | 04/17 10:15 | 19 | Max Alcala Gurri v Nicolas Alvarez Varona | 4-6,3-6 | |
| ATP Barcelona | 04/16 09:25 | 45 | [285] Nicolas Alvarez Varona v Philipp Kohlschreiber [126] | 3-6,7-5,7-6 | |
| Challenger - Madrid | 04/11 09:00 | 19 | [285] Nicolas Alvarez Varona v Oleksii Krutykh [338] | 1-6,2-6 | |
| Challenger - Madrid | 04/10 11:30 | 45 | [283] Nicolas Alvarez Varona v Carlos Gimeno Valero [379] | 6-7,6-4,6-2 | |
| Challenger Murcia | 04/06 12:40 | 25 | Nicolas Alvarez Varona v Daniel Merida Aguilar | 6-2,3-6,4-6 | |
| Challenger – Marbella | 03/31 15:50 | 26 | [89] Jaume Munar v Nicolas Alvarez Varona [298] | 6-4,6-2 | |
| Challenger – Marbella | 03/29 09:00 | 25 | [298] Nicolas Alvarez Varona v Lukas Klein [269] | 7-6,6-4 | |
| Challenger – Marbella | 03/28 09:45 | 19 | [298] Nicolas Alvarez Varona v Carlos Gomez-Herrera [438] | 4-6,5-7 | |
| Challenger – Marbella | 03/27 12:55 | 14 | [298] Nicolas Alvarez Varona v Petros Tsitsipas [227] | 6-2,6-1 | |
| Challenger Roseto | 03/15 12:45 | 25 | [186] Alessandro Giannessi v Nicolas Alvarez Varona [304] | 3-6,6-1,6-3 | |
| Challenger Roseto | 03/14 09:00 | 19 | [350] Louis Wessels v Nicolas Alvarez Varona [304] | 2-6,7-5,7-5 | |
| Challenger Roseto Qual | 03/13 12:20 | 14 | [497] Luca Potenza v Nicolas Alvarez Varona [304] | 5-7,6-7 | |
| 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 |
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.