Mosaic District- I have long said that the Mosaic District is GF paradise. They just keep getting better and better with gluten-free offerings. These restaurants all have GF menus available.
True Food Kitchen- http://www.truefoodkitchen.com/wp-content/uploads/2016/04/TFK-FF_Menu_FULL_web.pdf
Taylor Gourmet- http://www.taylorgourmet.com/
Jinya Ramen Bar- http://mosaicdistrict.com/dine/jinya-ramen-bar/
Cyclone Anaya's- www.cycloneanaya.com/vegetarian-gluten-free/
Springfield Town Center- The new Springfield mall is getting some great places that offer gluten-free options.
Zinburger- www.zinburgereast.com/assets/0416_zin_menu.pdf (Fantastic shakes and children's menu available as well)
Silver Diner- www.silverdiner.com/menu/chef-selections
Great American Restaurants- www.greatamericanrestaurants.com/
Both of these options are chains with locations available all over the NOVA area.
Clifton- This is one of my FAVORITE areas! It is such a cute little village with great historic charm and there are some great restaurants with GF offerings.
Trattoria Villagio- trattoriavillagio.com/about/ (GF pasta available and they will tailor make almost anything for you. Customer service is AMAZING!)
Trummer's on Main- www.trummersonmain.com/ (Probably my favorite restaurant in the entire NOVA area. Their brunch is to die for!)
The Clifton Cafe-www.cliftoncafe.com/ (Ask for them to make a GF crepe for you out of egg like an omelet)