Recent advances demonstrating quantum supremacy pose potential threats to the cryptographic integrity underpinning blockchain technology. As quantum computers progress towards realizing cryptographic breaks, blockchain networks face risks of compromise. This indicates an urgent need to upgrade cryptographic schemes securing blockchain ledgers and smart contracts. Understanding the nature and timeline of quantum threats will be critical for blockchain governance and protocols to properly prepare defenses. Additionally, the advent of quantum attacks requires reassessing legal frameworks and policies governing blockchain infrastructure. Regulations must address quantum risks, provide guidance to blockchain networks, stimulate research, and enhance consumer protections in a post-quantum era. By analyzing technical dimensions around quantum and blockchain while exploring policy implications, recommendations emerge for blockchain regulation and legislation for the coming quantum computing age.