We determine the parameters of a tokamak reactor plasma that attains ignition in the same regime of collisionality, νeiA/ωbe, as present-day Ohmic-heated tokamak plasmas. The 'collisional' regime is attractive because the presently observed confinement scaling, nτ ∝ n2, can be employed, and fusion power densities can be very large (∼10 W/cm3). The use of Nb3Sn toroidal field coils and a plasma elongation ⪆ 1. 5 are necessary to attain the high plasma density (n ≈ 5 × 1014 to 1015 cm−3) required for ignition in this low-temperature collisional regime.