The lithospheric architecture of the South China Block (SCB) is crucial to understanding the formation and evolution of this distinctive and highly reworked continental lithosphere with over 3 billion years of tectonic history. However, due to a lack of high‐resolution geophysical datasets, a detailed picture of the SCB lithosphere is absent, and fundamental questions regarding its formation, assembly, and subsequent reworking processes are actively debated. Assuming that unique deformation patterns due to such tectonic processes can be mapped by seismic anisotropy, we present a new crustal radially anisotropic shear‐wave velocity model along a 1500‐km seismic transect that spans the major tectonic domains of the SCB to characterize the past deformation processes. The new seismic models show significant lateral variations in seismic anisotropy and velocity, suggesting that the SCB consists of several separated (micro)continental blocks or terranes that likely have different origins and have survived the prolonged deformation history since the early formation of these continental fragments. Combining available geophysical datasets, we link individual crustal domains of distinct anisotropy to constrain the multiphase deformation processes of the SCB, including the early formation of the Proto‐Yangtze and Cathaysia Blocks, the assembly of the SCB, and the subsequent reactivation of the interior and extensive deformation that have formed the Basin‐and‐Range style tectonics in the Cathaysia Block. We suggest that relict continental fragments have played critical roles in the formation and reactivation of the SCB lithosphere. Plain Language Summary: The South China Block (SCB) is a significant landmass in eastern Eurasia with a history of over 3 billion years of tectonic activities. Despite its stable continent‐like appearance inferred from surface GPS measurements and scarce seismicity, the SCB exhibits a dichotomous path in its tectonic history, in which the Yangtze and Cathaysia Blocks evolved into a stable craton and a part of the continent that may have lost its root, respectively. This complex tectonic evolution is not well understood due to a lack of detailed information about the SCB's lithospheric structure. To address this, a dense seismic dataset was used to create a new radially anisotropic shear‐wave velocity model of the SCB's shallow lithosphere. This model helps to characterize past and current deformation processes by linking unique deformation fabrics to seismic anisotropy. The results reveal that the SCB consists of multiple blocks with distinct seismic properties. Combining with other geophysical and geological data, the new seismic information pieces together a better understanding of how the SCB formed and evolved over time. We conclude that these small pieces or fragmented crust of the SCB played a critical role in the assembly and reworking of the landmass. Key Points: A new crustal radial anisotropy model of the South China Block is presented using transdimensional ambient noise tomographyDistinct lateral heterogeneities in seismic anisotropy depicted as domains of crust with unique formation and evolution historySuch relict crustal fragments have played critical roles in forming and reworking of the South China Block lithosphere [ABSTRACT FROM AUTHOR]