  In the Standard Model (SM), the coupling of the electroweak gauge bosons to
the leptons is lepton flavour universal. Tests of this property constitute
sensitive probes for new physics models that violate lepton flavour
universality. Recent tests of lepton universality in rare $b\to s\ell\ell$
decays and semileptonic $b\to c\tau\bar{\nu}_\tau$ transitions have shown some
tensions with the precise SM predictions. These proceedings summarise the
latest results on lepton flavour universality from the LHCb experiment.
