The agreement was announced on Thursday, with Celta rewarding the 23-year-old for his development and performances under head coach Claudio Giráldez.
Rodríguez joined the club's A Madroa academy at the age of seven and worked his way through its youth teams. His route to the senior side was not always straightforward, with opportunities at youth level limited at times, but he persisted with his ambition to make it at Celta.
His breakthrough came during pre-season in 2024, when Giráldez called him into the first-team group to replace the injured Yoel Lago. Rodríguez seized the opportunity and did not return to the reserve side.
He made his first-team debut in the Copa del Rey against Turégano in November 2023 and subsequently established himself in the senior squad. Last season, he made 33 LaLiga appearances, starting 28 of them, and featured 12 times in the Europa League as Celta returned to European competition.
His performances also earned him a call-up to Spain's senior national team. Rodríguez made his international debut against Iraq in June, adding another milestone to a rapid rise from the club's academy.
He has now passed 90 competitive appearances for Celta and is approaching a century of games for the club he joined as a child.
Speaking to CeltaMedia after signing his new deal, Rodríguez said he was delighted to extend his stay.
“I am very happy and grateful to the club,” he said. “I made my debut in the first round of the season, and in that first season I did not expect to play so many matches. Then, playing in Europe in the second campaign was incredible.”
The defender also credited Giráldez with helping him improve physically, while acknowledging that there is still work to do.
“Claudio always told me to improve physically, and I think I have improved, but I can still do more,” Rodríguez said.
He added that he was building confidence with his teammates and wanted to improve both defensively and in attack.
The extension keeps a homegrown player at Celta through 2030 and reflects the club's commitment to developing talent from within its own academy.