My infix is somewhere in the Middle East,
Il is village in Iran.
My prefix annoy and make you muddy,
rile - to make angry, to stir from a state of calm.
My suffix a line, peculiar at least.
ley line - a supposed alignment of ancient geographical sites.
And I, concealed, is what you see!
Yes, this is a Riley.
My prefix on the road, is not an island,
RI is the state abbreviation of Rhode Island, most of which is located on the mainland of the United States.
My infix is three dots on the left.
l - in Braille is a line of three dots on the left.
My suffix is to Anglo-Saxons, an island.
ey - in Anglosaxon placenames, means island, as in Jersey & Guernsey.
And I, and I, when would I come back?
Two Rileys for the price of one - back again!!