Time–frequency (TF) analysis can be used as a useful tool to detect the global navigation satellite system (GNSS) code multipath (MP) and its frequency content. An accurate TF representation (TFR) is critical for highlighting the MP’s frequency signature and identifying its possible sources. The popular short-time Fourier transform (STFT) method has limitations in dealing with fast varying instantaneous frequencies, which are frequently observed in global navigation satellite system (GNSS) measurements due to MP. The wavelet-based synchrosqueezing transform (WSST) is a potential technique for providing a detailed high-resolution TFR. In this letter, we use WSST to perform TF analysis on both simulated and real-world data, demonstrating its utility in detecting code MP and its frequency content in urban environments. Based on the results, possible MP sources for the real datasets were identified. Furthermore, the proposed technique’s TF analysis results were validated using the ray-tracing method, demonstrating its effectiveness for MP detection.