Background: Endodontically treated teeth with substantial loss of coronal tooth structure may require fiber post placement for retention of the definitive restoration. The retention of fiber posts is influenced by the bonding between the post, luting cement, and root canal dentin. Aim: To comparatively evaluate the push-out bond strength of Tenax glass fiber posts cemented with RelyX U200, EsCem, and RelyX Luting 2. Materials and Methods: Forty-five extracted human permanent central incisors were decoronated, biomechanically prepared using ProTaper Gold files up to F3, and obturated with AH Plus sealer and F3 gutta-percha cones. Post spaces were prepared to a depth of 9 mm while maintaining a 4-mm apical seal. The specimens were randomly divided into three groups (n = 15): Group A (RelyX U200), Group B (EsCem), and Group C (RelyX Luting 2). Tenax glass fiber posts were cemented according to the respective group protocols. The specimens were sectioned to obtain coronal and middle root segments of 4 ± 0.1 mm thickness and subjected to push-out bond strength testing using a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed using one-way analysis of variance and Tukey’s post-hoc test. Results: The mean push-out bond strength in the coronal and middle thirds was 17.54 and 15.35 MPa for Group A, 15.95 and 15.05 MPa for Group B, and 14.25 and 14.64 MPa for Group C, respectively. A statistically significant difference was observed among the groups in the coronal third (p = 0.003). Conclusion: Within the limitations of the present in vitro study, RelyX U200 demonstrated the highest mean push-out bond strength among the tested luting materials, with a statistically significant advantage over RelyX Luting 2 in the coronal third.