The micro‐transfer‐printing of prefabricated C‐band semiconductor optical amplifiers (SOAs) on a silicon waveguide circuit is reported. The SOAs are 1.35 mm in length and 40 µm in width. Dense arrays of III‐V SOAs are fabricated on the source InP wafer. These can then be micro‐transfer‐printed on the target SOI photonic circuits in a massively parallel fashion. Additionally, this approach allows for greater flexibility in terms of integrating different epitaxial layer structures on the same SOI waveguide circuit. The technique allows integrating SOAs on a complex silicon photonic circuit platform without changing the foundry process‐flow. Two different SOA designs with different optical confinement factor in the quantum wells of the III‐V waveguide are discussed. This allows tuning the small‐signal gain and output saturation power of the SOA. The design with higher optical confinement in the quantum wells has a small‐signal gain of up to 23 dB and an on‐chip saturation power of 9.2 mW at 140 mA bias current and the lower optical confinement factor design has a small‐signal gain of 17 dB and power saturation of 15 mW at 160 mA of bias current.