While attention will focus on how Francis addresses the Rohingya Muslim crisis, the trip also holds huge significance for the tiny Catholic communities in each country.
Those Catholics face obstacles that include discrimination, an inability to land leadership roles and threats of violence. Many Christians hope the pope's visit will highlight the plight of the poor and of minority religious groups, including their own.
In Myanmar, Christianity is viewed by many as a colonial belief after the country was ruled by the British for a century until its independence in 1948.
The pope's visit to Bangladesh takes place against a backdrop of religious tensions after radical Muslims attacked or threatened to attack Christian priests and their followers.