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Atomically thin 2D transition metal dichalcogenides (TMDs), such as MoS₂, are promising candidates for nanoscale photonics because of strong light–matter interactions. However, Fermi‐level pinning due to metal‐induced gap states (MIGS) at the metal–monolayer (1L)‐MoS₂interface limits the application of optoelectronic devices based on conventional metals due to high contact resistance. On the other hand, a semimetal–TMD–semimetal device can overcome this limitation, where the MIGS are sufficiently suppressed allowing ohmic contacts. Herein, the optoelectronic performance of a bismuth–1L‐MoS₂–bismuth device with ohmic electrical contacts and extraordinary optoelectronic properties is demonstrated. To address the wafer‐scale production, full coverage 1L‐MoS₂grown by chemical vapor deposition. High photoresponsivity of 300 A W⁻¹at wavelength 400 nm measured at 77 K, which translates into an external quantum efficiency (EQE) ≈1000 or 10⁵%, is measured. The 90% rise time of the devices at 77 K is 0.1 ms, suggesting they can operate at the speed of ≈10 kHz. High‐performance broadband photodetector with spectral coverage ranging from 380 to 1000 nm is demonstrated. The combination of large‐array device fabrication, high sensitivity, and high‐speed response offers great potential for applications in photonics, including integrated optoelectronic circuits.