In the evolving landscape of power transformers, the integration of advanced technologies, such as high-performance polymers obtained by Fused Filament Fabrication (FFF), is crucial. This study investigates the compatibility and performance of various 3D-printed polymer materials—Biofila, polyvinylidene fluoride (PVDF), polyphenylene Sulfone (PPSU), polyetheretherketone (PEEK), polyetherimide (ULTEM 1010), and polyetheretherketone reinforced with 20% glass fiber (PEEK-GF20) for use in power transformer components. Through oil compatibility, dielectric strength, and kerosene compatibility evaluations, the study gauges their suitability for this application. The results reveal that PPSU, PEEK, and ULTEM 1010 exhibit promising characteristics, specifically in regard to dielectric breakdown voltage and kerosene and insulating oil compatibility. In contrast, Biofila presented severe cracking when exposed to the mineral oil and PVDF and PEEK-GF20 fall short in terms of dielectric strength, rendering them unsuitable. Kerosene compatibility assessments show minimal material changes, confirming that all studied materials have good resistance to this drying agent, commonly used on power transformers. This research aims to provides essential insights into material selection for a new generation of power transformer parts.