The highly-rated youngster has completed his move to Stamford Bridge. He leaves Devon after making 13 appearances for Exeter last season and becoming the club's youngest ever debutant at the age of just 15.
Despite only being 16, Ampadu has represented Wales at U19 level and was also called up to the senior squad ahead of the World Cp qualifier with Serbia in May.
Exeter will not receive a fee as such as Ampadu had not yet signed any sort of scholarship forms, however they will receive compensation, with talks ongoing between the sides as to a figure.
| Exeter City in negotiations with @ChelseaFC after @ethanamp4 agrees deal with @premierleague champions#ECFChttps://t.co/n8CrbKSC1U
— Exeter City FC (@OfficialECFC) 1 de julho de 2017