Mobile phone use is increasing among older adults, yet few studies have examined how the various purposes for which mobile phones are used affect loneliness and through what mechanisms. This study aims to address the gap by examining if different uses and gratifications of mobile phone are associated with loneliness and whether there is a mediation effect through face-to-face social interaction.

Participants included 1,318 mobile phone users drawn from a national probability sample of Japanese middle-aged (65% aged 40–64 years) and older adults (35% aged 65 years or older) in 2011. Ordinary Least Squares regression and mediation analyses were used.

Regression analyses revealed that using a mobile phone for sociability purposes was associated with decreased loneliness (b = −0.10, p < .001), while using it for the purposes of entertainment/passing time was associated with increased loneliness (b = 0.04, p < .01); some effects varied by age and mobile phone feature use. Further, sociability was associated with increased face-to-face social interaction, which was, in turn, associated with reduced loneliness. Passing time, however, was related to reduced face-to-face interaction and, in turn, an increased sense of loneliness.

Although it is not possible to determine causality from this cross-sectional design, it is possible that the various purposes for which mobile phones are used (specifically sociability and passing time) partially affect loneliness through their effects on either increasing or decreasing face-to-face social interaction. Recommendations for enhancing positive and reducing negative effects of mobile phone usage are discussed.