The VIA Classification of Strengths and Virtues attempts to provide a comprehensive model of character based on 24 character strengths. The present study is the largest study to date exploring the structure of the 24 strengths in youth. One sample (N = 23,850) completed the VIA-Youth, a teen measure of the VIA Classification. Based on a random subsample, it was determined the data were best modeled using four factors. The remainder of the sample was used to demonstrate measurement invariance for the four-factor model across ages 10-17 and country. Comparison with 471 English academy school students who completed two alternate measures of the VIA Classification also demonstrated measurement invariance. The results suggest a four-factor model that includes two primarily interpersonal factors, one reflecting general engagement, the second other-directedness. Other factors involved intellectual and self-control strengths. Implications for the understanding of character strengths in youth versus adults are discussed.