Maritime Administration Authorization Act for Fiscal Year 2023 This bill revises provisions related to the Maritime Administration (MARAD). Among other things, the bill reauthorizes MARAD programs, including programs associated with maintaining the U.S. Merchant Marine; requires MARAD to establish a United States Marine Highway Program to designate marine highway routes as extensions of the surface transportation system and provide grants and enter into contacts or agreements for marine highway services; directs the Department of Transportation (DOT) to develop and and deliver to Congress a strategy to assist state maritime academies and the U.S. Merchant Marine Academy to improve the representation of women and underrepresented communities in the next generation of the mariner workforce; directs DOT to develop a strategy to ensure there is an adequate supply of trained U.S. citizen mariners sufficient to meet the operational requirements of low- and zero-emission vessels; addresses sexual harassment and sexual assault at the U.S. Merchant Marine Academy and provides for greater diversity and inclusion at the academy and within the maritime transportation system workforce; and authorizes MARAD to award maritime career training grants to eligible institutions (e.g., postsecondary educational institutions or postsecondary vocational institutions) for the purpose of developing, offering, or improving educational or career training programs for workers in the United States related to the maritime workforce.