Nickel-based superalloys and additive manufacturing processes using nickel-based superalloys are disclosed herein. For example, a nickel-based superalloy includes, on a weight basis of the overall superalloy: about 9.5% to about 10.5% tungsten, about 9.0% to about 11.0% cobalt, about 8.0% to about 8.8% chromium, about 5.3% to about 5.7% aluminum, about 2.8% to about 3.3% tantalum, about 0.3% to about 1.6% hafnium, about 0.5% to about 0.8% molybdenum, about 0.005% to about 0.04% carbon, and a majority of nickel. Exemplary additive manufacturing processes include subjecting such a nickel-based superalloy in powdered build material form to a high energy density beam in an additive manufacturing process to selectively fuse portions of the build material to form a built component and subjecting the built component to a finishing process to precipitate a gamma-prime phase of the nickel-based superalloy.