Environmentally friendly, colorful, and flexible electrospun polyacrylonitrile (PAN)–carbon nanotubes (CNTs)–ochre (Oc) nanofibers (as-spun, stabilized) with very high flame resistance (heat release capacity of 24–143 J g−1 K−1, total heat release of 2.1–8.7 kJ g−1, char yield of 55–74%, limiting oxygen index of 22.5–34.5%) and mechanical properties (ultimate tensile strength of 80–177 MPa) were produced using a mineral, non-toxic, economic Oc and CNT in 1% CNTs and 10% Oc based on polymer concentration from a predominant synergistic effect between CNTs and Oc. This approach using a mineral material is an environmentally friendly method which may possibly solve a number of problems related to materials science and economics such as improving a flame resistance and lowering the cost for various applications in automobile, protective textile, and other areas.