Energy has been over time a sector of national interest and thus extremely vulnerable to risks. The emergence of new technologies revealed a new, unknown peril for the energy industry. Cyber threats are permanent and persistent risks that can disrupt energy supply and cause financial, environmental or any other kind of damage. This thesis offers a holistic approach to cybersecurity as a coordinated response to cyber threats. In the first chapter of this thesis is presented the evolution path of the energy sector, which is characterized by the energy transition that goes hand in hand with the digitization of the energy infrastructure and the market and organizational changes. Despite its positive contribution to the energy industry, this evolution has revealed many vulnerabilities and cyber threats that stakeholders need to overcome. In the second chapter, the interest is focused on answering some basic questions about the nature of cyber-attacks, the types, their origins, but most important the motives behind them and their severe impacts. What is more, some of the most popular cyberattacks in the energy sector are described in detail. The last chapter attempts to approach the notion of cybersecurity and correlate it to the broader concept of energy security. Deconstructing the doctrine of cyber governance, this thesis reaches some interesting conclusions about the proper environment and the actors that could achieve the ideal level of cybersecurity and bring this venture to fruition.