This paper presents a low-power, inductorless wideband cryogenic amplifier for superconducting nanowire single photon detector. To achieve wide bandwidth, low power consumption and small chip area, a modified Cherry–Hooper amplifier topology is used. With good input and output match, at 4.2 K temperature the measurement results show that the amplifier achieves 23-dB gain with a flat gain response, a 3-dB bandwidth of over 3.4 GHz, which covers frequencies as low as 130 kHz. Fabricated in a 0.13- μ m silicon germanium (SiGe) BiCMOS technology, the amplifier core occupies a silicon area of only 0.075 mm² and consumes a power of only 4 mW.