<p>Nonprobative photographs can enhance the perceived truthfulness of statements, a phenomenon known as the “truthiness effect.” Although this effect has been well established among young adults, less is known about whether older adults are similarly influenced. The present study (<i>N</i> = 375) examined the truthiness effect in both young and older adults and explored whether metacognitive reflection could reduce it. Results showed that both age groups were susceptible to the truthiness effect; however, the effect was more pronounced for true statements among young adults, whereas it was more evident for false statements among older adults. Individual differences in cognitive style did not moderate the truthiness effect, although higher Cognitive Reflection Test (CRT) scores were associated with more conservative truth judgments and better truth discrimination. Metacognitive reflection did not significantly attenuate the effect, although the overall pattern suggested a possible reduction, and it significantly improved participants’ ability to discriminate between true and false statements. These findings indicate that nonprobative photographs influence truth judgments differently in young and older adults, and suggest that metacognitive reflection prompts may be useful for improving judgment accuracy, with only limited evidence that they reduce the truthiness effect.</p>