Aubameyang only left the English capital in February as he departed Arsenal on bad terms and has no problem in teaming up with their rivals for the 2022/23 campaign.
The forward scored 68 goals in the Premier League for the Gunners and Thomas Tuchel will be eager for his new signing to pick up where he left off this time round.
On becoming a Chelsea player, Aubameyang said: “I’m really happy. It’s an honour to be part of this team and I can’t wait to start.
“I have some unfinished business with the Premier League so it’s good to be back and really exciting.”
How much have Chelsea paid for Aubameyang?
Despite signing Aubameyang on a free transfer seven months ago, Barcelona managed to make a profit on the striker as he joined Chelsea for €12 million (£10.3m).
However, this is much improved price for Chelsea than what Barca were originally asking for, with reports claiming they had demanded around £25m for the veteran.
It is also thought that Marcos Alonso’s move to the Nou Camp was also part of the deal, with the Spaniard’s departure also being confirmed on deadline day.
How much will Aubameyang earn at Chelsea?
It is unclear how much Chelsea will pay Aubameyang, however it is known that the former Arsenal star took a significant pay cut when he joined Barcelona and was earning only £80,000 a week.
This was a huge decrease on his whopping £350,000-a-week contract at the Emirates Stadium - a salary that Chelsea are unlikely to be paying.
What shirt number will Aubameyang wear?
Following Aubameyang’s confirmation in the early hours of the morning, Chelsea announced that he would be wearing the number 9 shirt.
The number 9 shirt is often thought to be ‘cursed’ due to the poor form of those who wear it - with Romelu Lukaku the last to sport the number.
However, Aubameyang is a proven goalscorer in the Premier League and will be eager to put an end to the ‘curse’.
Chelsea’s previous number 9s
• Romelu Lukaku - 36 apps, 10 goals
• Tammy Abraham - 76 apps, 26 goals
• Gonzalo Higuain - 16 apps, 5 goals
• Alvaro Morata - 69 apps, 20 goals
• Radamel Falcao - 12 apps, 1 goal
• Fernando Torres - 172 apps, 45 goals
• Franco Di Santo - 16 apps, 0 goals
• Steve Sidwell - 25 apps, 1 goal
• Khalid Boulahrouz - 23 apps, 0 goals
• Mateja Kezman - 41 apps, 7 goals
• Hernan Crespo - 73 apps, 25 goals
• Jimmy Floyd Hasselbaink - 177 apps, 87 goals
• Chris Sutton - 38 apps, 2 goals
• Gianluca Vialli - 84 apps, 40 goals
• Mark Stein - 54 apps, 23 goals
• Tony Cascarino - 45 apps, 8 goals