From only a single spoken word, listeners can form a wealth of first impressions of a person’s character traits and personality based on their voice. However, due to the substantial within‐person variability in voices, these trait judgements are likely to be highly stimulus‐dependent for unfamiliar voices: The same person may sound very trustworthy in one recording but less trustworthy in another. How trait judgements differ when listeners are familiar with a voice is unclear: Are listeners who are familiar with the voices as susceptible to the effects of within‐person variability? Does the semantic knowledge listeners have about a familiar person influence their judgements? In the current study, we tested the effect of familiarity on listeners’ trait judgements from variable voices across 3 experiments. Using a between‐subjects design, we contrasted trait judgements by listeners who were familiar with a set of voices – either through laboratory‐based training or through watching a TV show – with listeners who were unfamiliar with the voices. We predicted that familiarity with the voices would reduce variability in trait judgements for variable voice recordings from the same identity (cf. Mileva, Kramer & Burton, Perception , 48, 471 and 2019, for faces). However, across the 3 studies and two types of measures to assess variability, we found no compelling evidence to suggest that trait impressions were systematically affected by familiarity.