A fan assembly includes a bracket and a fan module. The bracket includes a ventilation plate. A limiting portion protrudes from the ventilation plate. The fan module is secured to the ventilation plate and includes a frame and a plurality of fan blades. The frame includes a first sidewall and a second sidewall opposite to the first sidewall. The plurality of fan blades are received in the frame, and each of the plurality of fan blades includes a first edge adjacent to the first sidewall and a second edge adjacent to the second sidewall. A height of the limiting portion is greater than a distance between the first edge and the first sidewall and smaller than a distance between the second edge and the second sidewall.