The former Arsenal and Barcelona man has failed to live up to expectations during his first 12 months at Stamford Bridge, managing just three goals from 21 appearances in his debut campaign.
Aubameyang is only under contract with Chelsea until the end of the 2023-24 campaign, and he was recently left out of Mauricio Pochettino's USA tour squad as his agents work on a departure.
Given the 34-year-old's extortionate wages, a move to Saudi Arabia was originally thought to have been the most likely outcome, as European teams had supposedly been put off by his salary demands.
However, Aubameyang has been reluctant to end his stint in Europe, and according to Fabrizio Romano, Marseille have now reached an agreement to bring the striker back to France.
The Gabon international is poised to sign a three-year contract with Les Olympiens until the summer of 2026, and Chelsea are apparently prepared to let him leave for free, despite having him under contract for another year.
Aubameyang is expected to touch down in Marseille's training camp in Germany tonight before undergoing his medical on Thursday, and his move should be finalised within the next 24 hours.
The 34-year-old plied his trade in France during the earliest stages of his career, representing Dijon, Lille, Monaco, Bastia and Saint-Etienne before joining Borussia Dortmund in 2013.
Aubameyang bids farewell to the Premier League having come up with 69 goals and 16 assists in 143 games during his spells with Arsenal and Chelsea, who will take a hit on the €12m (£10.4m) they paid for his services last year.
However, Pochettino will welcome Aubameyang's departure to free up more space on the Chelsea wage bill, and the Gabonese attacker will follow a surplus of unwanted players out of the exit door this summer.
Kai Havertz, Christian Pulisic and Mason Mount have all departed on permanent transfers following the signings of Nicolas Jackson and Christopher Nkunku, both of whom could make their Blues debuts against Wrexham in North Carolina on Wednesday.
David Datro Fofana has also joined Union Berlin on a season-long loan, while Baba Rahman, Ethan Ampadu, Edouard Mendy, Mateo Kovacic, Cesar Azpilicueta, Tiemoue Bakayoko, Kalidou Koulibaly, N'Golo Kante and Ruben Loftus-Cheek have also been axed.
More are expected to follow Aubameyang out of the exit door in the coming weeks, as none of Romelu Lukaku, Hakim Ziyech and Callum Hudson-Odoi made the trip to the USA either.
Ziyech saw a January loan move to Paris Saint-Germain collapse at the last minute over a documentation error, while a failed medical has already scuppered his chances of a lucrative switch to Al-Nassr in the current window.
Meanwhile, Juventus are thought to be leading the race to sign Lukaku, while Hudson-Odoi is supposedly of interest to Nottingham Forest and Fulham, the latter of whom have already seen a bid turned down.