Distributed quantum sensing exploits entangled states to estimate global functions of physical quantities with enhanced sensitivity beyond the standard quantum limit (SQL). In practice, however, unavoidable decoherence degrades quantum coherence and can lead to sensitivities lower than those of classical strategies. Here, we propose and experimentally demonstrate a noise-robust distributed quantum sensing protocol that employs local unitary operations to maintain enhancement beyond the SQL under dephasing. Using a four-photon Greenberger–Horne–Zeilinger state with the local Hadamard operations, we estimate the average of four phases distributed across four nodes via 7 km of optical fiber in a dephasing environment and observe enhancements from 1.72 ± 0.29 dB to 3.01±0.17 dB over the SQL. Our results establish a practical route to decoherence-resilient quantum sensor networks with currently available entangled resources.