Paint it the color of the wall and put a tall piece of furniture in front of it...like a bookcase, hutch, armoire etc. Or you could make it a window but would be permanent.

Caulk paint it & hang a sign on it of a saying on knob. Or mirror it.

Take it out and finish the opening inside and out.

Put a window there.

Where does the door go?

Create an alcove/hallway by putting up a folding screen/room divider in front.

if the door isn't needed,close the room and have it removed

The house is brick so to close it up or make it a window would be difficult because of matching brick, etc. Would the door on the left(to garage) look better if we trimmed around the opening?

Is the door to the garage a brick wall as well?

Yes, the door to the garage would look better with trim. Since the other door goes to the yard, you could try to match the brick as much as possible for the suggested window(however window would be off centered) - Whose going to see that the brick is not exact???

I would recommend living in the house for a while before you do anything drastic like close up doors. Usually it’s good to have a door that leads to the yard… Is there another door that leads to the yard? You might want to live there first and see how you utilize the space. If you do decide to keep the door, maybe you could change it to a glass panel door to make it a little more aesthetically pleasing.

I know one door leads to the garage, but is the other one there by code?

You will need to live there a bit to determine any good move. If it goes to a nice garden or patio then a nice pair of French Doors might be pretty. The other door looks recessed a bit so i don’t think that needs further trim work. Hard to tell from photos for sure though. Good luck.

Paint the unwanted door the same color as the wall, including the trim around it. Add trim to the garage door, and leave it white. Add some furniture and wall art to the wall beside the unwanted door.

If you want a window there but don't want to do construction, replace the unwanted door with a door that has a window. Again, paint the door the same as the wall, and put a curtain over it.

Could you replace the door with a large window., the same size as the door? That could look really good, and bring in some light. (Or maybe even a door that is all glass?)

I think your best bet would be to get rid of it entirely, but if that is not an option at the moment then I would do as others have suggested. To paint out that door and its trim the same colour as the wall would be the easiest way to help make it visually disappear. Depending on what you plan to do with the rest of that wall and traffic flow in/out the remaining door, I would then consider hanging some art on it or perhaps placing a decorative screen there?

Just be sure that you don't violate the fire codes if you close it off permanently.

If you put a window in, you wouldn't need to match any brick. Just fill below the window with a wood panel with a raised panel or some such so that it looks purposeful. Add a window box or shrubs and nobody's the wiser.