The 21-year-old is expected to undergo a medical check on Monday and sign an eight-year deal in a transfer that will surpass the previous highest figure of £105.8m the Blues paid Benfica for Enzo Fernández back in January.
Liverpool had a slightly lower bid accepted on Friday -- worth around £111m -- but sources confirmed to ESPN that the midfielder wanted to move only to Stamford Bridge. Sources suggest Chelsea will pay an initial £100m in guaranteed payments with a further £15m in add-ons. Around half of the add-ons are described as easily achievable with the other half considerably harder to trigger.
Sources had confirmed to ESPN that the 21-year-old made it clear he wanted to move to Stamford Bridge even after Liverpool agreed terms with Brighton, and Chelsea boss Mauricio Pochettino promised more signings would be on the way following a 1-1 Premier League draw with Jurgen Klopp's side.
"For sure we are going to improve the squad. It is about finding the right profile, the right player to create a combination maybe where we are more solid," Pochettino said Sunday.
Chelsea pulled out of a move to sign United States international Tyler Adams from Leeds amid a disagreement over the payment structure surrounding his £20m release clause and they decided instead to use that money to aid the pursuit of other options.
Caicedo had been Pochettino's No. 1 target all summer and the Argentine coach told ESPN in an exclusive interview last month that Chelsea were badly in need of midfield reinforcements.
In addition to Caicedo, Chelsea are hopeful of beating Liverpool to another midfielder as they pursue an agreement with Southampton for Romeo Lavia.
Liverpool have had at least three bids rejected by Southampton for Lavia, but Chelsea are believed to have indicated a willingness to offer more than the 19-year-old's £50m valuation.