Mutual funds have become an increasingly important investment option for individual investors by providing diversification, expert management, liquidity, and flexible investment opportunities. However, investors differ considerably in their scheme selection, investment mode, amount committed, investment horizon, and frequency of investment, reflecting variations in financial capacity and investment orientation. Despite the growing participation in mutual funds, limited regional evidence explains how socio-economic and demographic characteristics shape distinct investment patterns. Addressing this gap, the present study examines mutual fund investment patterns and their determinants among investors in Thiruvananthapuram District, Kerala. A structured questionnaire was used to gather primary data from 263 mutual fund investors employing a quantitative research approach. The findings revealed a significant association between scheme preference and investment horizon and identified three distinct segments: Systematic Growth-oriented Investors, Conservative Stability-Oriented Investors, and Active High-Value Investors. Systematic Growth-oriented Investors represented the largest segment (39.2%). Significant differences in investment patterns were observed across occupation, gender, monthly income, age, and investment experience. Monthly income and investment experience emerged as the most influential determinants of investor-cluster membership. The findings provide practical insights for mutual fund institutions and financial advisors to develop differentiated investment products, communication strategies, and advisory services aligned with heterogeneous investor profiles.