The talented youngster, who celebrated his 17th birthday on Friday, earned the deal after an impressive debut season with the club's academy during the 2025/26 campaign.
The winger became one of Wycombe's youngest first-team players when he made his senior debut in the Carabao Cup against Bromley last August.
Olabiyi later scored a dramatic stoppage-time winner on his EFL debut against Rotherham United in May, becoming the Chairboys' second-youngest EFL goalscorer, and recently netted in a pre-season friendly against Ebbsfleet United during pre-season preparations.
“We're hugely proud to celebrate Micah's birthday today by signing his first professional contract. Congratulations to him and all of his hard-work over the past 18 months of joining Wycombe Wanderers,” said Academy Director Jeremy Sauer.
"Since the Academy restarted, Micah has provided some significant milestones - he scored the academy's first goal against a professional club (Stockport County) in February 2025 and then the first academy goal for the first team at the end of last season.
"Today marks another exciting milestone. As one of the youngest in his age group, we've all had to be patient to secure him to the club for the long-term. This is another demonstration of how committed our club is to developing and producing academy players into our first team.
"He now has the platform to continue to make a further positive impression in the first team to hopefully go on and excite our supporters with goals and assists in the future.
"Lastly, congratulations to his family, his previous coaches and our own excellent recruitment team that brought Micah to the club. We all look forward to seeing his progress in the coming years at Wycombe Wanderers."