Chelsea have agreed a £40m-plus deal with United States-based sports technology firm Infinite Athlete to become the new front-of-shirt sponsor.
They had started the Premier League season without such a sponsor after their previous agreement with communications company Three expired.
The deal, for the 2023-24 season, covers both the men’s and women’s kits.
Chelsea’s women will wear the sponsored shirts for Sunday’s Women’s Super League opener against Tottenham.
The men’s team play Fulham on Monday.
The value of the deal places Chelsea among the Premier League’s top earners from shirt sponsorship, at a similar level to rivals Tottenham and Arsenal.
Liverpool’s deal with Standard Chartered is reportedly worth £50m per year, while earlier this month Manchester United announced a partnership from next season thought to be worth in excess of £60m a year.
Manchester City’s long-term deal with Etihad is estimated to be the most lucrative, at almost £70m a season.