A Coulomb blockade (CB) thermometer has been experimentally demonstrated based on the temperature dependence of a Ge quantum-dot (QD) single-hole transistor (SHT). The Ge-QD SHT features distinctive current peaks/plateaus, sharp differential conductance (GD) dips up to temperature 120K. The full-width-at-half minimum, V1/2, of the GD dips directly scale with temperature following the material parameter-independent equation of eV1/2 ∼ 5.44kBT, providing the primary thermometric quantity. Also the depths of the GD dips increases with 1/k BT as expected from CB theory of ΔGD/GD0 = EC/6kBT. This experimental demonstration indicates that our Ge-QD SHT offers an effective building block for ultrasensitive CB primary thermometers with the detection temperature as high as 115K.