AbstractWith the advancement of integration and miniaturization of precise instruments, the heat accumulating in electronic components is urgently needed to dissipate for ensuring their service life. In this work, boron nitride (BN) was functionalized with tannic acid/ferric ions (TA/Fe) chelate complexes to synthesize high thermally conductive natural rubber (NR) composites (NR@TA/Fe‐BN). The stable TA/Fe chelate complexes improved the interfacial compatibility between BN and NR and enhanced the BN dispersion in the NR matrix, which led to the reduction of interfacial thermal resistance and the construction of heat transfer channels in NR composites. As a result, a relative high thermal conductivity (0.327 W/(mK)) by 30 vol% NR@TA/Fe‐BN composite was achieved, being 2.44 times that of pure NR (about 0.134 W/(mK)). In addition, the insulating NR@TA/Fe‐BN composites showed outstanding elongation at break (686%) and tensile strength (15.2 MPa). This highly efficient and green TA inspired modification is expected to find application in industrial manufacturing of thermally conductive polymeric composites.