Eaton Vance Senior Income Trust is a closed-end fixed income mutual fund launched and managed by Eaton Vance Management. It invests in U.S. fixed income markets, primarily in senior secured floating rate loans issued by companies across diversified sectors. The fund benchmarks its performance against the S&P/LSTA Leveraged Loan Index. It was formed on October 30, 1998 and is domiciled in the United States.