The detrimental effects of Pb on the environment and human health have provided the driving force for replacement of Pb-Sn solders with Pb-free alternatives. Sn-rich Pb-free solder alloys with silver and copper alloying additions have higher strength but lower elongation-to-failure than Pb-Sn solders. Thus, these alloys are more susceptible to failure under mechanical shock, drop, and thermal fatigue conditions. In this article, mechanical tensile testing of NiTi-Sn3.5Ag single fiber composites demonstrates superelastic behavior of the composite with 85% strain recovery. Fatigue experiments show an evolution in damage over cycles, and an S-N curve shows sharp transition between a nearly vertical low-cycle fatigue behavior and the high-cycle fatigue regime. The solder composite exhibits constant fatigue strength over the superelastic range of the NiTi fiber.