Mid-infrared (MIR) silicon photonic systems show great promise for miniaturizing a variety of sensing and detection technologies. Rapid progress has been made in recent years, and numerous passive and active MIR devices have now been constructed on various silicon-based platforms. We previously reported the heterogeneous integration on silicon of Fabry–Perot and distributed feedback quantum cascade lasers (QCLs) operating at 4.8 μm. Interband cascade lasers (ICLs) will be preferred for many on-chip sensing technologies because they operate in the 3–6 μm range with threshold drive powers 1–2 orders of magnitude lower than QCLs. In this work, we demonstrate the integration of ICLs on a silicon substrate. These lasers emit 3.6 μm light into silicon-on-insulator waveguides in pulsed mode at temperatures up to 50°C. This represents an important step toward MIR photonic integrated circuits on silicon that operate with much lower drive power and therefore an even smaller footprint.