There is considerable academic and popular concern about the increasing gender gap in higher education enrollment in the United States. Males now constitute just 43% of the postsecondary enrollment. This research focused on nonmarital birth and father absence as predictors of lower levels of college enrollment for boys versus girls. The authors present two studies. In Study 1, using population data on college attendance and nonmarital birth rates, they found a strong positive association between nonmarital birth rates and the gender gap in college enrollment 18 years later. In Study 2, they examined individual‐level data on father absence from birth and college enrollment among young adults. The results indicated that males were at greater risk than females of not attending college if they had experienced father absence from birth. Taken together, the 2 studies suggest that changes in family structure may have contributed to the widening gender gap in higher education.