We investigated lifespan differences of confidence calibration in episodic memory, particularly the susceptibility to high-confidence errors within samples of children, teenagers, younger adults, and older adults. Using an associative recognition memory paradigm, we drew a direct link between older adults’ associative deficit and high-confidence errors. We predicted that only older adults would show high-confidence error even though their memory performance was at a similar level to that of children. Participants of all ages showed higher confidence following correct responses compared to incorrect responses, demonstrating the ability to calibrate subjective confidence in relation to memory accuracy. However, older adults were disproportionately more likely to indicate high confidence following erroneously remembered word pairs than participants of the other three age groups. Results are discussed in relation to the misrecollection account of high-confidence errors and ageing-related decline in hippocampus-dependent episodic memory functions.