Bayly, who was corporate responsibility and community investment manager at Lloyds, will oversee the consultancy's operations in Colombia, Chile and Peru in his role as head of the Andean region. He will report to Speyside CEO Ian Herbison.
Most recently, Bayly has worked for creative comms advisory firm Salterbaxter.
Bayly said: 'The Andean region is exciting, with high growth forecasts, a fast-growing middle class and much foreign direct investment.'
Herbison said: 'We see huge opportunities in the Andean region. Throughout Latin America, we are promoting an organic growth vision that combines local knowledge with international expertise and Josh will add significant value.'