Chelsea have completed a £37m deal to sign Ajax defender Jorrel Hato.

The 19-year-old has finalised a seven-year contract with the Blues after a medical in London over the weekend.

The Netherlands international has become the eighth signing of the summer transfer window for the FIFA Club World Cup champions.

"I'm very excited, I'm so happy to be here," said Hato.

"I thought a lot about my future and wanted to take the next step in my career. Chelsea is the best place for me to do that, so I'm very happy."

Hato emerged from Ajax's famed academy, making his debut in the first team aged 16.

Adept at left-back or centre-back, he captained the Dutch club at 17 and went on to make 111 appearances.

Hato made his international debut for the Netherlands in 2023 against Gibraltar and has six caps.

'Hato signing makes sense in Chelsea's bloated squad'

Matthew Hobbs, BBC Sport journalist

The Blues boast seven centre-backs in their current squad, but only Levi Colwill, who played regularly last season, and Benoit Badiashile are naturally left-sided.

Frenchman Badiashile's 2024-25 campaign was disrupted by a hamstring injury in December, while just three Premier League starts suggested head coach Enzo Maresca wanted another option to compete with Colwill at the heart of defence.

Hato brings versatility, having spent large parts of last season at Ajax playing at left-back and, with Ben Chilwell firmly out of favour, the 19-year-old can also offer competition to regular full-back Marc Cucurella given the Champions League campaign to come.

In 2023-24, Hato played 80% of his football at centre-back, most commonly in a 4-2-3-1 formation. However, last season, new head coach Francesco Farioli deployed him at left-back for 94% of his minutes as part of a 4-3-3 formation.

Hato has already played 111 competitive games for Ajax's first team, after making his debut aged just 16 years and 335 days in 2023. That made him the club's third youngest player to feature in Eredivisie after Clarence Seedorf and Ryan Gravenberch. He also won his first Netherlands cap less than a year later.

Since that first appearance, Hato has been nearly ever-present for Ajax. Of players from Europe's top six leagues born after 1 January 2003, he has played the most minutes at club level in all competitions since the start of 2023-24 (8,347), clear of Jude Bellingham (7,988) and Lamine Yamal (7,506).

Who have Blues brought in this summer?

Hato is Chelsea's eighth addition to the squad this summer, with their spending so far reaching a combined sum of more than £250m.

Jamie Gittens - £48m from Borussia Dortmund. The England youth international arrives from the Bundesliga with a growing reputation as a direct, pacy winger capable of unlocking defences.

Joao Pedro - £55m from Brighton. Chelsea moved swiftly to secure the Brazilian forward, who impressed in the Premier League with his creativity, link-up play and finishing.

Liam Delap - £30m from Ipswich Town. A powerful striker with Premier League experience, Delap adds a different profile to Chelsea's attacking options.

Mamadou Sarr - £12m from Lyon. The 19-year-old centre-back joins as one for the future, bringing strength and composure in defence after progressing through Lyon's academy.

Dario Essugo - £18m from Sporting CP. A highly rated Portuguese midfielder, Essugo is known for his tenacity and maturity, having debuted in Liga Portugal at 16.

Estevao Willian - the Brazilian winger joined the Blues from Palmeiras this summer in a £29m deal that was agreed in May 2024.

Kendry Paez - a £17m deal to sign the Ecuadorian teenager was agreed in 2023, but he has linked up with Chelsea this summer after turning 18 in May.