Sinensetin (SIN) is an important active compound that exists widely in citrus plants, and has been reported to exhibit various pharmacological properties, including anti-oxidative, anti-inflammatory, and anti-tumor. This study was designed to examine whether SIN can protect against amyloid beta (Aβ)-induced neurotoxicity and to elucidate the underlying mechanism. Our results showed that pretreatment with SIN for 1 h, followed by co-treatment with Aβ plus SIN for 24 h, attenuated Aβ-induced cell viability reduction, oxidative stress, inflammation, and apoptosis in a dose-dependent manner. Aβ-induced upregulation of Toll-like receptor 4 (TLR4) expression and nuclear translocation of nuclear factor-kappaB (NF-κB) p65 subunit were inhibited by pretreatment with SIN. Furthermore, the protective effect of SIN was abrogated by TLR4 overexpression. Hence, our data suggested that SIN attenuated Aβ-induced neurotoxicity through the TLR4/NF-κB pathway.