  We compute four-point functions with two maximal giant gravitons and two
chiral primary operators at three-loop order in planar $\mathcal{N}=4$
Super-Yang-Mills theory. The Lagrangian insertion method, together with
symmetries of the theory fix the integrand up to a few constants, which can be
determined by lower loop data. The final result can be written in terms of the
known three-loop conformal integrals. From the four-point function, we extract
the OPE coefficients of two giant gravitons and one non-BPS twist-2 operator
with arbitrary spin at three-loops, given in terms of harmonic sums. We observe
an intriguingly simple relation between the giant graviton OPE coefficients and
the OPE coefficients of three single-trace operators.
