The stable isotopic composition of insoluble, refractory elements such as titanium (Ti) or zirconium (Zr), which are modified by magmatic differentiation but, a priori, are poorly affected by weathering or diagenesis, serve as powerful potential proxies to reconstruct the compositional evolution of the continental crust. Here we present the evolution of the Zr stable isotopic compositions (${\delta }^{94/90}$Zr_IPGP-Zr, per mille deviation of ⁹⁴Zr/⁹⁰Zr from IPGP-Zr standard) of the continental crust through time, using 38 sedimentary samples from the upper continental crust (UCC), including 12 Holocene loesses from the Chinese Loess Plateau and Xinjiang, three oceanic sediments from the sea floor outboard of the Lesser Antilles island arc and 23 glacial diamictite composites with depositional ages ranging from ∼ 2.9 Ga to 0.3 Ga from South Africa, South America, Canada, USA and China. The samples show limited Zr isotopic variations with ${\delta }^{94/90}$Zr_IPGP-Zr values of 0.043‰ - 0.109‰ for loess; 0.069‰ - 0.083‰ for oceanic sediments and 0.031‰ - 0.118‰ for glacial diamictites; their Zr-weighted average values are, 0.081 ± 0.044‰ (2SD, n = 12), 0.073 ± 0.015‰ (2SD, n = 3) and 0.078 ± 0.047‰ (2SD, n = 23), respectively. The isotopic similarity among loess, oceanic sediments and glacial diamictites, suggests that zircon enrichment effects previously documented in some sedimentary samples have not biased the Zr isotope compositions of these sedimentary rocks from their source rocks. Two groups with or without Zr enrichment have similar average ${\delta }^{94/90}$Zr_IPGP-Zr values (0.075 ± 0.040‰ and 0.080 ± 0.046‰). There is no correlation between Zr isotope compositions and any proxy of chemical weathering (e.g., Al₂O₃/SiO₂, Fe₂O₃/SiO₂, CIA, K₂O/Al₂O₃ and ${\delta }^7$Li). The ${\delta }^{94/90}$Zr_IPGP-Zr values are quite constant for these sedimentary samples regardless of their depositional ages and locations. Therefore, the UCC appears to have had a constant Zr isotopic composition between 3 Ga and present, and is homogeneous at a large scale. Combining data for sedimentary reference materials from the literature and the sedimentary rocks in this study, we suggest a Zr-weighted ${\delta }^{94/90}$Zr_IPGP-Zr value of 0.077 ± 0.058‰ (2SD, n = 44) for the UCC, which is statistically distinct (t test, p value = 2.88 × 10⁻¹⁰) and higher than that of the mantle (0.040 ± 0.044‰, n = 72). Combining the ${\delta }^{94/90}$Zr_IPGP-Zr values of different terrestrial reservoirs, the ${\delta }^{94/90}$Zr_IPGP-Zr of the BSE and bulk Earth is constrained to be 0.041 ± 0.041‰.