Dirac electrons lead to unusual electronic and optical properties in graphitic materials (graphene, carbon nanotubes). Near-field optical nanoscopy is a powerful tool to study material properties at the nanometer scale. In this talk, I will first introduce the scanning near-field optical microscopy (SNOM) technique. Then I will discuss layer-stacking domain walls in bilayer graphene and its novel valley transport behavior. I will also talk about near-field optical imaging of Luttinger-liquid plasmons in single-walled carbon nanotubes.