Realty Income Corporation (NYSE: O) is widely considered the gold standard among monthly dividend-paying companies. Officially trademarked as "The Monthly Dividend Company," this prominent retail real estate investment trust (REIT) is an S&P 500 Dividend Aristocrat boasting a multi-decade track record of uninterrupted monthly distributions, backed by a defensive triple-net lease portfolio leased to recession-resistant tenants. Other top-tier choices include Main Street Capital (MAIN) for high-yield monthly BDC income and Agree Realty (ADC) for high-credit commercial portfolios.