Despite the potency of Financial Technology (FinTech) in facilitating financial inclusion, the determinants of the diffusion in Small and Medium-Sized Enterprises (SMEs) remain intricate. Consequently, the study assesses the determinants of the diffusion of FinTech Payment Services (mobile money, card, and online payments) by SMEs in the context of Ghana. We sample 407 registered SMEs with the Association of Ghanaian Industries (AGI) and employ hierarchical logistic regression models to explore the multiplicative effects of SMEs Chief Executive Officers Characteristics (CEOC), Business Characteristics (BUSC), and FinTech Payment Service Characteristics (FPSC) on the Diffusion of FinTech Payment Services (DFPS). Consistent with the technology diffusion theories, the finding reveals that CEOC, BUSC, and FPSC altogether determines the DFPS in Ghanaian SMEs. Thus, the combined effects of human, business, and technology actors drive the DFPS in SMEs. Therefore, the optimal design of FinTech services is critical for mass diffusion by SMEs in emerging economies.