A novel fiber Bragg grating (FBG) tilt sensor with simple and stable structure is proposed to detect the magnitude as well as the direction of a two-dimensional inclination by using four FBGs with different reflective wavelengths. High angle sensitivity and measurement resolution are achieved and the temperature effect is eliminated completely without additional temperature compensation schemes. Preliminary results verified the feasibility of the proposed idea and showed that the tilt angle accuracy and resolution of the FBG tilt sensor are very good. Resolution of about 0.3° has been achieved. It is important to emphasize that the performance of the FBG tilt sensor can be further improved. The accuracy and resolution of the sensor can be easily increased by either using a heavier weight or decreasing the angle between the hanging fibers.