Background: The role of processed foods in nutrition transition in the Pacific is receiving some attention in the context of a significant obesity and diet-related noncommunicable disease health burden. However, trends, patterns and underlying drivers of processed food markets in the Pacific are not well understood. The aim of this study was to investigate recent trends and patterns of processed food markets in the region and interpret the findings by engaging key literature on relevant food systems drivers. Methods: We conducted a mixed-methods approach involving two steps; (1) We analysed Euromonitor market sales data for processed food and beverage products sold from 2004–2018 for 16 countries differentiated by income level, and (2) guided by a food systems conceptual framework, we drew upon key literature to understand the likely drivers of our observations. Results: We observed plateaus and declines in processed food sales in some high-income countries but increases in upper-middle and lower-middle income countries, and most rapidly in the latter. Beverage markets appear to be stagnating across all income groups. Carbonated soft drinks, baked goods, vegetable oils, processed meats, noodles and sweet biscuits made up the majority of sales in transitioning countries. These observations are likely a result of income growth, urbanising populations, trade and globalisation, and various policies implemented by Pacific governments. Conclusions: A processed foods nutrition transition is well underway in the Pacific region and accelerating most prominently in lower-middle income countries.