This dataset contains survey data collected for the study “TikTok Usage in the UK and USA: Investigating the Role of Demographic Factors, Personality Traits, and User Motivation.” The research examined how demographic characteristics, personality traits, and motivations for use predict patterns of TikTok engagement among adults in the United Kingdom and the United States. Data were collected using an online survey distributed via the participant recruitment platforms Prolific and Sona Systems. The final sample consisted of 361 adult participants aged 18–68 years. Participants self-reported their TikTok usage over the previous week, including hours spent on TikTok and number of times the app was opened. Usage was recorded across three time periods: day-time (6:00–22:00), night-time (22:00–6:00), and total weekly usage. In addition to usage metrics, the dataset includes measures of demographic variables (age, gender, nationality), personality traits, and user motivations. Personality was measured using the Big Five Inventory-10 (BFI-10), which assesses extraversion, agreeableness, conscientiousness, neuroticism, and openness. Motivations for TikTok use were measured using the Motives for TikTok Use scale, capturing dimensions such as socially rewarding self-presentation, trendiness, escapist addiction, and novelty.