In this work, we find that La-doped BaSnO3 (BLSO) is shown to be a promising electromagnetic shielding transparent conductor. While films grown on industrially practical optoelectronic MgAl2O4 substrates have higher sheet resistance by three orders of magnitude than in previous reports, we show how to recover the sheet resistance close to the single-crystal level by use of an MgO template layer which enables high quality (001)-oriented BLSO epitaxial film growth on (001) MgAl2O4. There is a positive correlation between crystallinity and conductivity; high crystallinity minimizes scattering of free electrons. By applying this design principle to 5-20% doped films, we find that highly crystalline 5% La-doped BLSO films exhibit low sheet resistance of ~ 8.7 Ω ▯ -1, high visible transmittance of ~ 80%, and high X-band electromagnetic shielding effectiveness of ~ 25.9 dB, thus outperforming transparent conducting oxides films of Sn-doped In2O3 and SrMoO3.