17.07.2023 Carlos Alcaraz is both the youngest world No. 1 (19 years, 4 months) tennis player, and the youngest year-end No. 1 (19 years, 7 months). Federer is the oldest No. 1 (36 years, 10 months), while Djokovic is the oldest year-end No. 1 (34 years, 7 months).