High-resolution synchrotron X-ray tomography combined with digital volume correlation (DVC) enables characterization of three-dimensional strain fields. When local tomography is used to investigate specimens larger than the field of view (FOV), the resulting subvolumes must be stitched together to form a single volume, thereby introducing strain uncertainties in DVC analyses. The present work quantifies such strain uncertainties obtained from extended-FOV synchrotron X-ray tomography of an Al99.5 metal matrix syntactic foam. To achieve this, zero-strain repeated scans were performed on the specimen. Two local DVC strategies, regular-grid DVC and discrete DVC, were applied to the stitched volumes to quantify the spatial distribution and magnitude of strain uncertainties. Both approaches confirm a consistent spatial hierarchy of strain uncertainties. Non-overlapping regions exhibit uncertainties of approximately 0.06%, while overlapping regions show uncertainties of approximately 0.17% (Frobenius norm of the Green–Lagrangian strain tensor). The spatial distribution of strain uncertainty in the stitched volume indicates that uncertainties in overlapping regions are two to four times higher compared to non-overlapping regions. The zero-strain stitching uncertainty quantification method demonstrated here is recommended as a standard pre-characterization step for any DVC study involving stitched tomographic volumes.