In December, at the 2021 World Short Course Championships in Abu Dhabi, United Arab Emirates, Martinenghi won the silver medal in his first event, the 100 metre breaststroke, with a time of 55.80 seconds, which was 0.10 seconds slower than the gold medalist and world record holder in the event Ilya Shymanovich."Nuoto, Mondiali vasca corta. Nicolò Martinenghi super! Argento nei 100 rana uomini" (in Italian). Eurosport. 17 December 2021. Retrieved 28 January 2023. Helping achieve a third-place finish with a 1:37.29 in the final of the 4×50 metre mixed medley relay for his second event, he won a bronze medal for his efforts.FINA (18 December 2021). "15th FINA World Swimming Championships (25m) Abu Dhabi (UAE): Mixed 4x50m Medley Relay Final Results". Omega Timing. Retrieved 28 January 2023. For his third event, he split a 25.30 for the breaststroke leg of the 4×50 metre medley relay, helping win the bronze medal with a final time of 1:30.78.FINA (20 December 2021). "15th FINA World Swimming Championships (25m) Abu Dhabi (UAE): Men's 4x50m Medley Relay Final Results". Omega Timing. Retrieved 28 January 2023. In his fourth event, his second of two individual events, he won the silver medal in the 50 metre breaststroke with a time of 25.55 seconds.Tiseo, Giandomenico (21 December 2021). "Nuoto, Mondiali vasca corta: Nicolò Martinenghi argento nei 50 rana a un soffio dall'oro!" (in Italian). OA Sport. Retrieved 28 January 2023. Concluding competition with his fifth event, he split a 55.94 for the breaststroke leg of the 4×100 metre medley relay to help achieve a new Championships and Italian record time of 3:19.76 with finals relay teammates Lorenzo Mora (backstroke), Matteo Rivolta (butterfly), and Alessandro Miressi (freestyle) and win the gold medal.FINA (21 December 2021). "15th FINA World Swimming Championships (25m) Abu Dhabi (UAE): Men's 4x100m Medley Relay Final Results". Omega Timing. Retrieved 28 January 2023.
