  We propose a search for long lived axion-like particles (ALPs) in exotic top
decays. Flavour-violating ALPs appear as low energy effective theories for
various new physics scenarios such as t-channel dark sectors or
Froggatt-Nielsen models. In this case the top quark may decay to an ALP and an
up- or charm-quark. For masses in the few GeV range, the ALP is long lived
across most of the viable parameter space, suggesting a dedicated search. We
propose to search for these long lived ALPs in $t\bar{t}$ events, using one top
quark as a trigger. We focus on ALPs decaying in the hadronic calorimeter, and
show that the ratio of energy deposits in the electromagnetic and hadronic
calorimeters as well as track vetoes can efficiently suppress Standard Model
backgrounds. Our proposed search can probe exotic top branching ratios smaller
than $10^{-4}$ with a conservative strategy at the upcoming LHC run, and
potentially below the $10^{-7}$ level with more advanced methods. Finally we
also show that measurements of single top production probe these branching
ratios in the very short and very long lifetime limit at the $10^{-3}$ level.
