When people ask which president had the highest inflation rate, they’re usually looking for a single, definitive name. Which president had the highest inflation rate depends on timeframe. All-time since CPI records began (1913): Woodrow Wilson, with annual CPI inflation peaking near 18% in 1918 during WWI. Peak annual CPI versus average annual CPI over a term will change the headline. ConclusionAnswering which president had the highest inflation rate is simple on its face—Wilson all-time (1918), Carter in the modern era (1980; highest average).