Self-regulation and social cognition flourish as children begin school and engage with a new social environment. At the same time, this novel setting provides more complex social situations that children must navigate, including understanding when others may be lying to them. Social cognition and self regulatory abilities, such as Theory of Mind (ToM) and executive function (EF) respectively, may aid children in understanding such advanced social situations by helping children consider others' viewpoints and focus on problem solving (Garte, 2016; Kultti & Pramling, 2015; Winsler, Fernyhough, & Montero, 2009). In order to investigate these possible relations, children between the ages of 3 and 5 (N= 92, M = 51.42 months, SD = 8.86, range = 37 to 69 months; 49 males; 38 3-year-olds, 31 4-year-olds, 23 5-year-olds) completed a battery of EF skills, ToM, and implausible lie detection measures. Results indicated that EF skills significantly predicted implausible lie detection, over and above both age and ToM. Findings are discussed in terms of the unique contribution that self-regulation skills, such as EF, make to young children's blossoming implausible lie detection ability.