The 2D tungsten disulfide (WS2), as a typical transition metal dichalcogenide (TMD), has aroused intense research interests in photodetection. However, the limited detection wavelength ranges and low photoresponsivity hinder its further application. To promote the application of WS2 in optoelectronics fields, indium arsenide (InAs) nanoislands decorated WS2 are utilized to fabricate photodetectors in this work. Owing to the photogating effect and localized surface plasmon resonance (LSPR), a significant enhancement of photocurrent response (≈1 mA W−1) is obtained by coupling WS2 with InAs nanoislands. Furthermore, the extended detection wavelength up to 1060 nm is realized due to the efficient light absorption in IR range of InAs nanoislands. The high performance, stability, and reliability in ambient temperature strongly indicate that the InAs nanoislands/WS2 heterostructure can be considered as a promising material for TMDs‐based broadband optoelectronic devices in the future.