Single crystals of the polytellurides RETe1.8 of gadolinium, terbium, and dysprosium were prepared by chemical vapor transport and alkali metal halide flux reactions. To determine proper synthesis conditions for the desired target composition, the binary phase diagram Gd‐Te was evaluated by CalPhaD methods. The compounds are isostructural to SmTe1.8 and crystallize in space group P4/n (no. 85) with lattice parameters of a = 966.10(4), 960.00(3), and 957.33(2) pm and c = 1794.15(10), 1785.77(6), and 1779.38(5) pm for GdTe1.8, TbTe1.8 and DyTe1.8, respectively. The structures consist of puckered [RETe] double slabs and planar telluride layers composed of Te2 dumbbells and linear Te3 units in accordance with ELI‐D based bonding analyses. The latter can be understood as a Te34– anion. GdTe1.8 is a semiconductor with a bandgap of 0.19 eV/0.17 eV (experimental/calculated). Magnetization data confirm trivalent RE ions and indicate antiferromagnetic order at TN = 12 K for TbTe1.8 and TN = 9.8 K for DyTe1.8, whereas GdTe1.8 remains paramagnetic down to 2 K.