A method of fabricating a saddle-fin transistor may include: forming a buffer oxide film and a hard mask oxide film over a semiconductor substrate; etching the buffer oxide film, the hard mask oxide film and the semiconductor substrate corresponding to a mask pattern to form a trench corresponding to a gate electrode and a fin region; oxidizing the exposed semiconductor substrate in the trench to form a gate oxide film; depositing a gate lower electrode in the trench; and depositing a gate upper electrode over the gate lower electrode to fill the trench.