A new spectrally selective coating based on carbon nanotubes (CNTs) for solar thermal applications is demonstrated. For optimized coatings solar absorptance coefficients α>0.92 and thermal emittance coefficients ε<0.1 (400°C) were achieved. These results render CNT coatings as a low cost and high performance alternative to commercially available vacuum deposited cermet coatings for concentrated solar power (CSP) application.