The 26-year-old Udinese goalkeeper was sanctioned for alleged betting irregularities and was suspended in July.
He was accused of 'match manipulation' as a result of a yellow card he received during Udinese's 2-1 Serie A victory over Lazio in March 2024.
Okoye made his club return in a 1-1 draw with Cremonese on Monday and expressed his delight on social media.
The player posted: "Happy to be back, back to doing what I love most.
"Back to fighting alongside my teammates, back to fighting in front of our fans, back to doing what I am doing since a young boy.
"Back to following the path my father fought for, back to having fun, back to chasing dreams, back to doing what I'll die for."
Okoye has 19 national team caps and will now be eligible to fight for a place in the Super Eagles' World Cup squad.