A fuel sender assembly for a vehicle may include a main housing which is mounted at a reservoir cap and is provided with a boss therein, a variable resistance unit which is mounted inside the main housing and is provided with a ceramic resistance plate having a ground resistance, a contact arm unit disposed at an upper portion of the ceramic resistance plate and rotatably mounted at the boss inside the main housing, a main cover which has a penetrating hole in a corresponding position to the boss and is mounted at a front surface of the main housing, a float arm having one end which is bent and is rotatably mounted at a front surface of the main cover and the other end, and a float mounted at the other end of the float arm so as to rotate the float arm according to the residual fuel.