Wataru Endo was born on 9 February 1993 in Yokohama and began his professional career at J1 League side Shonan Bellmare. A composed defensive midfielder who reads the game as well as he tackles it, he was instrumental in Shonan's run to the J2 title in 2014, scoring seven goals in 38 league matches as the club returned to the top flight.
A move to Urawa Red Diamonds in 2016 raised his profile dramatically. He scored the winning penalty in the J.League Cup final shoot-out that same year, and in 2017 he lifted the AFC Champions League — the most prestigious club title in Asian football. In 2018 he moved to Belgium with Sint-Truiden, then on to VfB Stuttgart in 2019, first on loan and then permanently. His four years in the Bundesliga proved highly productive: he topped the league for most duels won and was constantly among the top players for tackles and possession recovered. In May 2022 he scored a stoppage-time winner against 1. FC Köln to keep Stuttgart in the Bundesliga, a moment Stuttgart fans still talk about.
In August 2023 Liverpool signed Endo for around €19 million. His EFL Cup triumph in 2023–24 was followed by a Premier League title in 2024–25 — a first for any Japanese player as a regular squad member of a champion English side. He has since added the 2025 Community Shield to his cabinet.
Endo made his Japan debut in August 2015 and has captained the side since June 2023. He started every match at the 2022 FIFA World Cup, where Japan reached the round of 16, and led the team at the 2023 AFC Asian Cup.