Specific heat, magnetic susceptibility, and electrical transport measurements were performed at ambient pressure on high quality single-crystal specimens of $\mathrm{Ce}\mathrm{Rh}{\mathrm{In}}_5$ down to ultralow temperatures. We report signatures of an anomaly observed in all measured quantities consistent with a bulk thermodynamic phase transition to a superconducting state at $T_c=110\mathrm{mK}$. Occurring far below the onset of antiferromagnetism at $T_N=3.8K$, this transition appears to involve a significant portion of the available low-temperature density of electronic states, exhibiting an entropy change in line with that found in other members of the 115 family of superconductors tuned away from quantum criticality.