Grego-Cox joined the club 12 months ago and made 32 appearances in his debut season for the Reds. He scored his first League goals in a 3-1 win at Exeter on Good Friday.
Speaking to crawleytownfc.com head coach Gabriele Cioffi said: "I am delighted for Reece that he has signed this contract extension.
"He made good progress last season and I know he is capable of a lot more. He has a great attitude and wants to work hard which I like. I am hoping that this is a big season for him."