  Accurate, experimental rovibronic energy levels, with associated labels and
uncertainties, are reported for 11 low-lying electronic states of the diatomic
\TiO\ molecule, determined using the \Marvel\ (Measured Active
Rotational-Vibrational Energy Levels) algorithm. All levels are based on lines
corresponding to critically reviewed and validated high-resolution experimental
spectra taken from 24 literature sources. The transition data are in the 2 $-$
22,160 \cm{} region. Out of the 49,679 measured transitions, 43,885 are
triplet-triplet, 5710 are singlet-singlet and 84 are triplet-singlet
transitions. A careful analysis of the resulting experimental spectroscopic
network (SN) allows 48,590 transitions to be validated. The transitions
determine 93 vibrational band origins of \TiO\, including 71 triplet and 22
singlet ones. There are 276 (73) triplet-triplet (singlet-singlet) band-heads
derived from \Marvel\ experimental energies, 123 (38) of which have never been
assigned in low or high resolution experiments. The highest $J$ value, where
$J$ stands for the total angular momentum, for which an energy level is
validated is 163. The number of experimentally-derived triplet and singlet
\TiO\ rovibrational energy levels is 8682 and 1882, respectively. The lists of
validated lines and levels for \TiO\ are deposited in the Supporting
Information to this paper.
