  In this work we investigate single crystal GdTiO$_{3}$, a promising candidate
material for Floquet engineering and magnetic control, using ultrafast optical
pump-probe reflectivity and magneto-optical Kerr spectroscopy. GdTiO${}_{3}$ is
a Mott-Hubbard insulator with a ferrimagnetic and orbitally ordered ground
state (\textit{T${}_{C}$} = 32 K). We observe multiple signatures of the
magnetic phase transition in the photoinduced reflectivity signal, in response
to above band-gap 660 nm excitation. Magnetic dynamics measured via Kerr
spectroscopy reveal optical perturbation of the ferrimagnetic order on
spin-lattice coupling timescales, highlighting the competition between the
Gd${}^{3+}$ and Ti${}^{3+}$ magnetic sub-lattices. Furthermore, a strong
coherent oscillation is present in the reflection and Kerr dynamics,
attributable to an acoustic strain wave launched by the pump pulse. The
amplitude of this acoustic mode is highly dependent on the magnetic order of
the system, growing sharply in magnitude at \textit{T${}_{C}$}, indicative of
strong magneto-elastic coupling. The driving mechanism, involving
strain-induced modification of the magnetic exchange interaction, implies an
indirect method of coupling light to the magnetic degrees of freedom and
emphasizes the potential of GdTiO${}_{3}$ as a tunable quantum material.
