We report the discovery of four new hot Jupiters with Next Generation Transit Survey (NGTS). NGTS-15b, NGTS-16b, NGTS-17b, and NGTS-18b are short-period ($P<5$d) planets orbiting G-type main sequence stars, radii masses between $1.10-1.30$ $R_J$ $0.41-0.76$ $M_J$. By considering host star luminosities planets' small orbital separations ($0.039-0.052$ AU), we find that all highly irradiated ther...