The 21-year-old has agreed a Bundesliga move, with Chelsea happy for the England forward to head out on a temporary switch.
Chelsea were determined to keep Hudson-Odoi in the long term, with Blues bosses hoping the talented attacker can find full sharpness and form at Leverkusen.
Hudson-Odoi had been the subject of strong interest for both permanent transfer and loan options, with the likes of Newcastle and Southampton both courting the former England youth star.
But a loan move to the Bundesliga suits all parties, with Hudson-Odoi itching for regular game time.
Hudson-Odoi ruptured his Achilles tendon in 2019 just when he looked prime to bring his rich potential to bear on the Premier League.
The wide forward has battled for minutes under Thomas Tuchel after shaking off that injury however.
Chelsea’s summer revamp under new owners Todd Boehly and Behdad Eghbali has looked to put an even greater squeeze on Hudson-Odoi’s first-team chances in west London this season.
But neither the Blues nor Hudson-Odoi were thought to be ready to give up on him making the grade at Chelsea in the long-run.