We show that the organic salt 4‐N,N‐dimethylamino‐4′‐N′‐methyl‐stilbazolium tosylate (DAST) is a very interesting material for electro‐optic applications in the near infrared. The electro‐optic coefficients, namely r 111, r 221, r 331, r 113, r 223, and r 333, were determined in the spectral range of 700 up to 1535 nm using optical samples cut from large high quality bulk crystals. DAST combines large electro‐optic coefficients, e.g., r 111=77±8 pm/V at λ=800 nm and r 111=47±8 pm/V at λ=1535 nm, with low dielectric constants, e.g., ε1=5.2±0.4. This combination leads to large polarization‐optical coefficients.