The literature on representation has shown that those who reflect the characteristics, traits, and/or experiences of a group (descriptive representation) are more likely to represent that group’s interests (substantive representation). In this paper, we argue that questions about representation should be considered with regard to generational identity. Drawing upon research that shows the importance of the Millennial Generation identity for understanding Millennials’ attitudes and policy preferences, we look at whether this identity matters for the legislative representation of group interests by examining bill sponsorship activity in 31 state legislatures. Our results tentatively support the expectation that the Millennial generation identity conditions the sponsorship of Millennial interest bills. Millennial legislators are more likely than non-Millennial legislators to sponsor bills that disproportionately impact their group members. This result is observed among both Democrat and Republican legislators, but at different magnitudes and for different issue priorities. These findings suggest that the Millennial generation identity is a meaningful determinant of legislative behavior, even when examined alongside partisanship.