A panel of experts selected the 27-year-old as one of the two star central defenders of the 2021-21 campaign.
Tunnicliffe has been named alongside Cheltenham Town s Will Boyle in the heart of the Team of the Year's backline.
The defender has, to date, made 42 appearances in all competitions, and has found the net five times this season.
Tunnicliffe has helped the Reds keep 15 clean sheets in the league and played a huge part in dumping Leeds United out of the FA Cup.
The centre-half scored the third goal in Crawley's famous 3-0 victory over the Whites in the third round back in January.
Tunnicliffe said: "I'm very happy personally. Obviously it's a personal award but, and I know it's cliche, I couldn't have done it without the lads this year.
"I think we've done really well as a unit and as a team. I think it shows how well we've done this year.
"Personally, I'm really proud to receive the award."