We present the confirmation of the eccentric warm giant planet TOI-201 b, first identified as a candidate in Transiting Exoplanet Survey Satellite photometry (Sectors 1-8, 10-13, and 27-28) and confirmed using ground-based photometry from Next Generation Transit Survey and radial velocities from FEROS, HARPS, CORALIE, and Minerva-Australis. TOI-201 b orbits a young (0.87-0.49+0.46, Gyr) and bright (V = 9.07 mag) F-type star with a 52.9781 day period. The planet has a mass of 0.42-0.03+0.05, MJ, a radius of 1.008-0.015+0.012, RJ, and an orbital eccentricity of 0.28-0.09+0.06; it appears to still be undergoing fairly rapid cooling, as expected given the youth of the host star. The star also shows long-term variability in both the radial velocities and several activity indicators, which we attribute to stellar activity. The discovery and characterization of warm giant planets such as TOI-201 b are important for constraining formation and evolution theories for giant planets.