Former Sheffield United player McFadzean (23) won the manager's player of the season award for 2009/10, and his signature means he will be at the Impact Arena until May 2012.
McFadzean's season is not yet finished as he will be joining up with the
England 'C' semi-professional squad for away games against both Scotland and Ireland.
The FA Representative XI take on an East of Scotland League at Spartans FC in Edinburgh this Saturday, then England take on the Republic of Ireland in Waterford on Wednesday, 26th May for the International Challenge Trophy.
Law said: "He is a big part of what we are trying to achieve, and if we are going to achieve things we have got to keep our best young players. We are obviously delighted with Kyle's decision to stay with us for the next two years."
Very importantly, Law now has a terrific platform on which to build as nine of his squad are committed to the cause on at least one year contracts with last season's top scorer Paul Clayton also signed to May 2012.
Law added: "It was important we get the core strength of the squad tied up as soon as possible, and we have negotiations ongoing with several other players as well as chasing new targets."
Also contracted with the Reds to May 2011 are Ian Ross, who has penned a new one-year deal, plus Anton Brown, Aden Flint, Liam Hearn, Anthony Howell, Dominic Roma and Ben Mills.
Meanwhile, Law has added a very attractive pre-season home game against Conference Premier Division club Luton Town to his summer itinerary.
This will take place at the Impact Arena on Saturday, July 24th with a 3pm kick-off.
And with Chesterfield set to visit on Saturday, July 17, and a full-strength Mansfield Town side expected on Saturday, August 7, the Reds squad will be assured of some very good tests before the Blue Square North season begins a week later than usual on August 14. The 2010/11 campaign will end on Saturday, April 30, 2011.