United States-Israel Cybersecurity Cooperation Enhancement Act of 2021 This bill requires the Department of Homeland Security to establish a grant program that contributes to the homeland security capabilities of both the United States and Israel by supporting cybersecurity research and development as well as the demonstration and commercialization of cybersecurity technology. Grant applicants must address a requirement in the area of cybersecurity research or cybersecurity technology and be comprised of a joint venture between a U.S. entity and an Israeli entity (or the governments of each country).