The Conference Board Consumer Confidence Index, which had increased in August, improved further in September.
The index now stands at 104.1 (1985=100), up from 101.8 in August.
The present situation index rose from 125.3 to 128.5, while the expectations index improved from 86.1 last month to 87.8.
Director of economic indicators Lynn Franco said: "Consumer confidence increased in September for a second consecutive month and is now at its highest level since the recession.
"Consumers' assessment of present-day conditions improved, primarily the result of a more positive view of the labour market. Looking ahead, consumers are more upbeat about the short-term employment outlook, but somewhat neutral about business conditions and income prospects. Overall, consumers continue to rate current conditions favourably and foresee moderate economic expansion in the months ahead."