Previous research has examined young and middle-aged adults' perceptions of child witnesses; however, no research to date has examined how potential older adult jurors may perceive a child witness. The present investigation examined younger (18-30 years, N = 100) and older adults' (66-89 years, N = 100) liedetection and credibility judgments when viewing children's truthful and dishonest reports. Participants viewed eight child interview videos where children (9-11 years of age) either provided a truthful report or a coached fabricated report to conceal a transgression. Participants provided lie-detection judgments following all eight videos and credibility assessments following the first two videos. Participants completed a General Lifespan Credibility questionnaire to assess credibility evaluations across various witness ages. Lie-detection results indicated that older adults had significantly lower discrimination scores, a stronger truth bias, and greater confidence compared to younger adults. Older adults also rated children as more competent to testify in court, credible, honest, believable, and likeable than younger adults. Participants with greater differences in their credibility evaluations for truth and lie-tellers were significantly more accurate at detecting lies. Responses to the Lifespan Credibility questionnaire revealed significant differences in younger and older adults' credibility evaluations across the lifespan.