Transportation and handling of molten sulfur is inherently complex due to the unique rheological behavior of sulfur at differing temperatures. Upon melting at 115 °C, sulfur's viscosity remains close to 10 × 10-3 Pa∙s until reaching T > 160 °C, the λ-transition region, where the viscosity dramatically increases to a maximum of ca. 93000 × 10-3 Pa∙s at 187 °C. This research reports and examines the modifying effects of hydrogen sulfide (H2S) within liquid sulfur due to its relevance and association within prominent industrial processes, e.g., Claus sulfur recovery or sulfuric acid production. Using the experimental data from this study, a semi-empirical correlation model was produced based on the reptation model of Cates to estimate the impact of H2S on liquid sulfur’s viscosity as a function of temperature. The correlation model yields a final fit value of R2 = 0.9983. Also within this work, previous studies on the non-Newtonian rheometric properties of liquid elemental sulfur are revisited and discussed. Past misinterpretation of apparent behavior is attributed to instrumental artifacts. Additionally, this research examines experimental evidence for the relaxation behavior of liquid sulfur through the use of oscillation-based measurement.