The National League South Promotion Final winners must take on the new division without the inspirational centre-back.
Okoye’s form played a big part in the club’s promotion but Bradley Quinton now must find a replacement with the Iron so far signing no new players.
The defender took to twitter to announce he wouldn’t be remaining at Cressing Road.
“As painful as it is for me to say, I won’t be staying at Braintree Town,” he wrote.
“My first thank you have to be directed towards Bradley Quinton and his staff, a top manager and a top person. He allowed me to develop my game and mature.
“Thank you to all the fans who supported us through every win loss or draw. You kicked every ball with us.
“I can’t put into words my gratitude for every single person associated with Braintree Town.
“The club will sit in my heart and it has been an honour to lead the boys.
“I have banked some memories that works would not do justice.”
PHOTO BY CHRIS JARVIS