  We report on the absolute frequency determination of the 5s5p $^1P_1$ - 5s5d
$^1D_2$ transition in atomic strontium, achieved through frequency
comb-referenced laser-induced-fluorescence (LIF) spectroscopy. We excite the
5s$^2$ $^1S_0$ - 5s5p $^1P_1$ transition using an on-resonance laser at
$\approx$461 nm, and then measure the variation in the LIF signal while
scanning the laser at $\approx$767 nm across the 5s5p $^1P_1$ - 5s5d $^1D_2$
transition. We determine the absolute frequency of $390599571.7\pm0.4$ MHz,
with an accuracy that surpasses the previous most accurate measurement by two
orders of magnitude. This measurement technique can be readily applied for
precision spectroscopy of high-lying states not only in strontium, but also in
other atomic species.
