This is a dynamic list of persons who have made major contributions to the (mainstream) development of general relativity, as acknowledged by standard texts on the subject. Some related lists are mentioned at the bottom of the page.
Yvonne Choquet-Bruhat (formerly Yvonne Bruhat; local existence and uniqueness of solutions to the vacuum Einstein equations, initial value formulations, textbook),
George F. R. Ellis (relativistic cosmological models, classification of curvature singularities, averaging problem in cosmology, gauge-invariant linear perturbations of spatially homogeneous cosmologies, "small universes," monograph, Virbhadra–Ellis lens equation),
Frederick J. Ernst (Ernst vacuum family, Ernst equation, solution generating methods, Ernst–Wild electrovacuum),
Loránd Eötvös (Weak Equivalence Principle experiment)
Richard Feynman (sticky bead argument [as 'Mr. Smith'], supermassive stars, derivation of the Einstein field equations from quantum field theory, Feynman Lectures on Gravitation),
K. S. Virbhadra (Virbhadra–Ellis lens equation Virbhadra–Ellis lens equation, relativistic images [1], photon surfaces [2], observational test for the weak cosmic censorship hypothesis [3][4]),
George Volkoff (Tolman–Oppenheimer–Volkoff limit, Tolman–Oppenheimer–Volkoff equation)