The Belgian striker re-joined the Blues in a deal just shy of £100million last summer, but has struggled for form having netted just eight Premier League goals in the 2021/22 season.
But he has now returned to Italy, having revealed he was in contact with Inter manager Filippo Inzaghi 'all last season'.
A statement from Chelsea read: "Romelu Lukaku will spend the 2022/23 campaign with Inter Milan after completing a season-long loan move from Chelsea."
The short, matter-of-fact statement went on to mention the highlights of Lukaku's past season without offering any comment.
News of the transfer was also confirmed in a short video posted by Inter in which the player said he was 'very happy'.
The Serie A outfit followed with another tweet which read: "Welcome back Rom".
Asked what convinced him to move back to the San Siro, he said: "The affection of the fans and my team-mates, but also the opportunity to work with the coach.
"I stayed in contact with him all last season. I think the coach is doing well with the team. I want to contribute and do good for this club.
"It's like coming home," he added. "I think my family and I had a really good time in Milan thanks to the people, the fans and my team-mates. From the first day when I arrived here everyone helped me a lot, I'm really happy.
"I didn't even leave my home when I went to England, which shows how happy I am to be back here. Now I just want to see the guys on the pitch."
"Inter have given me so much and I hope now to do even better than before."
It's a move that will be a welcomed relief for both clubs, with Inter looking to regain the Serie A title that Lukaku played a huge role in them winning in the 2020/21 season.
Meanwhile, Chelsea have cut ties with a player for next season who made it clear how unhappy he was at the club less than six months after re-signing.
In the explosive interview with Italian media, Lukaku also revealed his intentions to return to the Nerazzurri.
"Physically I am fine. But I'm not happy with the situation at Chelsea," Lukaku said in December 2021.
"Thomas Tuchel has chosen to play with another system - I won't give up, I'll be professional. I am not happy with the situation but I am professional - and I can't give up now."
Lukaku added: "It wasn't meant to happen like that. The way I left Inter, the way I communicated with the fans, this annoys me, because this might not be the right time to say it, but back then it didn't feel like the right moment either.
"Now I think it's right to speak, because I said that I will always have Inter in my heart and I genuinely hope to one day go back to play there. I am in love with Italy, this is the time to let people know what really happened, without bad-mouthing anyone, because that's not my style.
"Now it's the right time to share my feelings. I have always said that I have Inter in my heart: I know I will return to Inter, I really hope so. I am in love with Italy, this is right moment to talk and let people know what really happened."
He continued: "I want to apologise to Inter fans, because I think the way I left should've been done differently. I should've spoken to you first, because the things you did for me, for my family, my mother, my son, those will stay with me for the rest of my life.
"I really, genuinely from the bottom of my heart hope to come back to Inter, not at the end of my career, but while I am still at the level to win more trophies."
His wish has now been granted and upon completing his return to Inter, Lukaku's words were rather apt when remembering what he said in December.
Stood alongside Inter president Steven Zhang told their club media: "I'm very happy to be back.
"It seemed impossible for me to come back here but we made it and for this I must also thank him [Zhang]. He continued to push and believe that it was possible. In the end we succeeded. I'm very happy."