This document reviews research on using nanofluids to improve the performance of flat plate solar collectors. Nanofluids are fluids containing nano-sized particles that can enhance heat transfer properties. Several studies have found that nanofluids can increase heat transfer coefficients and collector efficiencies compared to using plain water. Specifically, alumina, copper oxide, and carbon nanotubes dispersed in water have shown efficiency improvements of up to 29% relative to water alone. Higher nanofluid concentrations and lower flow rates tend to increase efficiency, up to an optimal point. Overall, the literature demonstrates that nanofluids have promising potential to enhance flat plate solar collector performance.