The singlet excited-state lifetime of a bipyridyl platinum(II) complex containing two alkynyl-benzothiazolylfluorene units was determined to be $145\pm 105\text{\hspace{0.17em} ps}$ by fitting femtosecond transient difference absorption data, and the triplet quantum yield was measured to be 0.14. A ground-state absorption cross section of $6.1\times {10}^{-19}{\text{cm}}^2$ at 532 nm was deduced from UV-visible absorption data. Excited-state absorption cross sections of $\left(6.7\pm 0.1\right)\times {10}^{-17}{\text{cm}}^2$ (singlet) and $\left(4.6\pm 0.1\right)\times {10}^{-16}{\text{cm}}^2$ (triplet) were obtained by using a five-level dynamic model to fit open-aperture Z scans at picosecond and nanosecond pulse widths and a variety of pulse energies. For this complex, the ratio of the triplet excited-state absorption cross section to the ground-state absorption cross section—long used as a figure of merit for reverse saturable absorbers—thus stands at 754, to our knowledge the largest ever reported at 532 nm wavelength.