The American Tree Sparrow is a small sparrow with a long notched tail. The adult has a streaked back and wings, with two white wing bars, but is otherwise unstreaked, while the juvenile is streaky overall. Adults have an unstreaked gray-brown breast and belly, with a dark spot in the center. The tail, rump, and nape of the neck are all solid gray. The upper mandible of the bill is dark and the lower is yellow. The head is mostly gray, with a rufous crown and eye-line.