Expanding Opportunity through Pre-Apprenticeships Act This bill requires the Office of Apprenticeship (OA) within the Department of Labor to create a plan to expand participation in pre-apprenticeship programs for underrepresented populations and individuals with barriers to employment, and requires Labor to award related grants to certain eligible entities (e.g., community-based organizations, pre-apprenticeship sponsors, and employers for an in-demand industry or occupation). Specifically, the bill establishes pre-apprenticeship program standards and requirements; directs Labor to collect data on pre-apprenticeship programs, using workforce innovation and opportunity indicators of performance, on how programs resources are spent, and on the diversity and equal opportunity in apprenticeship programs; directs the OA in partnership with state apprenticeship agencies to conduct research in state labor markets and create a plan to expand participation in registered pre-apprenticeship programs for nontraditional populations or individuals with barriers to employment such as youth, women, people of color, long-term unemployed, individuals with disabilities, individuals with substance abuse issues, individuals impacted by the criminal justice system, and veterans; and provides grants to serve participants from nontraditional apprenticeship populations with preference to women, people of color, veterans, those who have been impacted by the youth or adult criminal justice system, and individuals with barriers to employment between the ages of 16 and 24.