Decellularized uterine extracellular matrix (dUECM) is promising for uterine tissue engineering because of its inherent bioactivity and structural complexity. However, transforming dUECM into porous, functional 3D constructs remains a significant challenging. This study aimed to (1) synthesize dUECM using a modified decellularization protocol and formulate it into a hydrogel ink and (2) fabricate 3D-printed constructs from this ink to assess their capacity to support human uterine myometrial cell growth in vitro. Porcine uterine tissues were decellularized using 1% Triton™ X-100 with varying concentrations of sodium dodecyl sulfate (SDS) (0.1-1.5%) for 48-72 hours. The resulting dUECM was characterized using DNA and glycosaminoglycan (GAG) quantification, picrosirius red-polarized light microscopy, routine histology, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and thermogravimetric analysis (TGA). To prepare the ink, dUECM powder was enzymatically digested with pepsin and subsequently blended with 2% and 3% alginate to obtain a printable hydrogel formulation. Constructs were fabricated using extrusion-based 3D printing and assessed for filament fidelity, swelling, degradation behavior, and mechanical properties. Biocompatibility was evaluated using hTERT-HM myometrial cells through MTT metabolic assays, Live/Dead staining, and immunohistochemical (IHC) α-SMA staining. The optimal protocol (1% Triton™ X-100 + 1% SDS for 48 h) reduced DNA to 51.3 ± 9 ng/mg while retaining a high level of GAGs (54.9 ± 7.6 µg/mg). Preservation of the ECM structure was confirmed by spectroscopy analyses. The 3% Alg + 1.5% dUECM hydrogel exhibited suitable printability (1.5 ± 0.2), swelling capacity (47 ± 12%), degradation resistance (94 ± 18% mass retention), and mechanical strength (decreasing from 323 kPa to 175 kPa over 14 days), along with high viability and proliferation (258 ± 13%). The developed dUECM-based hydrogel supports 3D bioprinting with strong mechanical and biological performance, offering a promising platform for uterine tissue engineering.