A double-pass L-band erbium-doped fiber amplifier with tunable gain clamping is demonstrated by using a linear laser cavity configuration formed by a pair of fiber Bragg gratings at the wavelength of 1565 nm. A C/L-band wavelength division multiplexer is used to split the signal in the L-band which is then reflected by an optical circulator-based loop mirror to form a double-pass configuration. A variable optical attenuator (VOA) is inserted into linear laser cavity to tune gain clamping. Experimental results show that the clamped-gains are 13.05, 20.83 and 26.29 dB for VOA settings of 0, 9 and 15 dB, respectively. The corresponding dynamic gain-clamped range of the input signal power is up to -5, -10 and -15 dBm respectively, and variations of clamped-gain are less than 0.34 dB.