Epithermal neutron capture and transmission measurements were performed using the time-of-flight method at the Rensselaer Polytechnic Institute linac using metallic Nb samples. The capture measurements were made at the 25-m flight station with a 16-section sodium iodide multiplicity detector and the transmission measurements at the 25-m flight station with a 6Li glass scintillation detector. Resonance parameters were determined for all resonances up to 500 eV with a combined analysis of capture and transmission data using the multilevel R-matrix Bayesian code SAMMY. The results are compared to those presented in ENDF/B-VI, updated through Release 3.