A bidirectional optical transceiver includes a wavelength-selecting filter, an optical fiber, a transmitting module, and a receiving module. The wavelength-selecting filter is placed on an optical axis, passes a first optical signal therethrough, and reflects a second optical signal perpendicularly to the traveling path of the second optical signal. The optical fiber has a face that is opposite to the wavelength-selecting filter and is inclined at an angle of φ with respect to a normal line perpendicular to the optical axis. The transmitting module is placed on the optical axis in opposition to the optical fiber with respect to the wavelength-selecting filter and has a light source for generating the first optical signal and outputting the generated first optical signal to the wavelength-selecting filter at an inclined angle with respect to the optical axis.