Vegan or Vegetarian in DC?
Will be in town this week with a car and Metro access.
There are always veggie options on menus throughout the city. However, if you want a vegetarian restaurant, Java Green downtown is highly recommended (tons of vegan options), and there is also Vegeate. Asylum in Adams Morgan has a vegan brunch. For sweets check out the vegan bakery, Sticky Fingers, in Columbia Heights. They are known for their vegan cinnamon buns.
Nirvana on K St. near Farragut West (I think?) is great, completely vegetarian Indian food. Vegan/gluten free is marked separately on the menu. Pretty little space.
Java Green also has a whole vegdc publication, which you should pick up while you're in town if you want to stay strictly vegetarian. But most places offer a vegetarian option, if you stay away from the obvious no-no's like BBQ/stolid steakhouses (well, some of those have vegetarian options too, they're just an afterthought and it's not a great test of the kitchen.) Have fun!
Sticky Fingers also has food now. And, around the corner is a Julia's Empanada's which has great vegetarian empanadas. In adams morgan, amsterdam falafal is yummy - and Tryst has good vegetarian options. As does Open City in Woodley.
Spices in Cleveland Park has great vegetarian options. Suicide Curry, if you dare.
Spices is a good recommendation.
My vegan officemate told me recently that he had a nice meal at Perry's in Adams Morgan where they had vegan and vegetarian options plus a lot of sushi and small plates for his meat-eating companions. I've personally never been there but it's another options.
Also Heritage, a great Indian restaurants in Dupont Circle (and Glover Park), has vegetarian options.
Java Green has wonderful food, but their service has gone south in the last 6 months, IMO. It's a madhouse at lunch, but has outdoor seating so dinners can be quite nice.
For upscale, Nora's is expensive, but fantastic and a wonderful atmosphere. Not 100% veg, but much (all?) organic and several veg options.
If you are outside the city, Sunflower Cafe (two locations: Vienna and Falls Church near 7 Corners) is wonderful and has a nice atmosphere.
Lastly, I would also recommend Duangarat's in Falls Church/Bailey's Crossroads. It's a Thai and is not 100% veg, but has many veg options to choose from.