Investing in Tomorrow's Workforce Act of 2021 This bill (1) directs the Department of Labor, beginning after the earlier of submission of the Government Accountability Office's study on automation or October 1, 2022, to award grants to eligible partnerships to support demonstration and pilot projects relating to the training needs of workers who are, or are likely to become, dislocated workers as a result of automation; (2) expands training programs for such workers, including activities that prepare the individuals for occupations in the technology sector; (3) authorizes the award of national dislocated worker grants to provide employment and training assistance to workers affected by advances in automation technology; and (4) expands funding for national dislocated worker grants.