Safe from the Start Act of 2021 This bill directs the Department of State to direct U.S. foreign assistance to address humanitarian crises in a manner that aims to prevent and respond to gender-based violence at the onset of an emergency. The State Department shall focus on (1) preventing gender-based violence, (2) protecting survivors of humanitarian crises from the onset of the emergency, (3) promoting standards and activities to prevent and respond to gender-based violence, and (4) advancing and empowering survivors and at-risk individuals. Activities shall include improving access to post-sexual-assault medical and mental health services and ensuring such services are available to hard-to-reach populations. The State Department may provide support to local and international organizations to achieve its goals.