We conducted a genome-wide association study on income among individuals of European descent (N=668,288) to investigate the relationship between socioeconomic status and health disparities. We identified 162 genomic loci associated with a common genetic factor underlying various income measures, all with small effect sizes. Our polygenic index captures 1-5% of income variance, with only one-fourth due to direct genetic effects. A phenome-wide association study using this index showed reduced risks for diseases including hypertension, obesity, type 2 diabetes, depression, asthma, and back pain. The income factor had a substantial genetic correlation (0.92, s.e.=0.006) with educational attainment (EA). Accounting for EA's genetic overlap with income revealed that the remaining genetic signal was linked to better mental health but reduced physical health and increased risky behaviours such as drinking and smoking. These findings highlight the complex genetic influences on income and health.