I am in Seattle for a conference every year or so, and navigate around a smallish part of the city - hence why everything is clumped near each other!
If you're in Seattle, probably one of the main attractions you will be told to visit is the Pike Place Market. I'm not even going to try to explain to you the ins and outs of this world famous market - just check the link to explore! I have eaten here, and there are probably more options than I'm listing. There are a few sit down restaurants that I haven't yet tried. There are also TONS of restaurants in an easy walking distance. There is also a Target just up the street that carries gluten free groceries if you needed to stock up or were staying at a place you could cook. Anyway, these are my go-to's in the actual market:
1536 Pike Pl, Seattle, WA 98101
Cinnamon Works is a small walk-up bakery that offers vegan, gluten-free, and sugar-free options. They take precautions to avoid cross-contamination, but this is not a gluten free bakery. I get something here every time I visit (I usually stay in a hostel right next to Pike Place).
1514 Pike Pl, Seattle, WA 98101
A little soup, sandwich and bakery place that has been around since 1912, is the first business licensed to a woman in Seattle, and is the longest continually operating business in Pike Place! Though they don't list gluten free on the menu, I stopped in one day and asked just to see. Turns out they had gluten free bread and the owner knew all about cross-contamination and went out of their way to be careful for me. In the times after that, I found a mixture of understanding, but everyone was very willing to go out of their way to accommodate. The pastries are not gluten free, but just around the corner from the main bakery area, they have a small eating counter and make a good lunch that is gluten free. Now I eat there every time I'm in the area!
Wherever food trucks go, check out the website for locations
This meal is one of my favorites, and it comes in a food truck! They make 100% gluten free quinoa bowls that are mostly organic, and you can get vegetarian or vegan versions. And they serve it with a gluten free cookie (ingredients are listed online)! Find this place, and eat happily!
407 Olive Way, Seattle, WA 98101
I was searching for a gluten free breakfast place to meet a friend, and this one came up on a number of searches. It was very nicely decorated at some point in the 90's, and could use an updating, but that's not the point of finding gluten free food, right? They have a gluten free menu and tons of options - meaning, not just eggs. I had the Shakshuka which turned out to be pretty amazing!