The Blues are understood to be paying an initial £100m, plus £15m in performance-related add-ons.
Caicedo has been granted permission by Brighton to have a Chelsea medical, which is expected to take place on Monday.
The midfielder will sign an eight-year contract, with the option of a further year.
Brighton will have a sell-on clause that has been described as “significant” as part of the £115m deal to sell Caicedo.
The Blues will pay £100m up front for the midfielder, with £15m in add-ons.
Half of the add-ons have been described as “quite easily achievable”, while the other half are considered “much harder” to achieve.
Liverpool agreed a £111m deal to sign Caicedo earlier this week but the move fell through when the 21-year-old informed the club he intended to join Chelsea.
Caicedo had been expected to travel to Liverpool for a medical on Friday after Jurgen Klopp’s side had a bid accepted by Brighton following a midnight deadline for bids on Thursday.
But the Ecuador international had a change of heart and told Liverpool – who drew 1-1 at Chelsea in their opening Premier League game of the season on Sunday – he did not want to join.
Caicedo instead remained in London and made it clear he only wanted to leave Brighton for Chelsea, who have been pursuing him all summer.
The £115m fee eclipses the £106.8m Chelsea paid for Enzo Fernandez when breaking the British-record transfer fee in January.