The European Ombudsman is generally considered one of the most prominent EU actors promoting transparency and access to documents. Under Article 228 TFEU, she has a mandate to supervise maladministration in the activities of the EU institutions, bodies, offices and agencies, and within this context the Ombudsman has produced considerable work in the area of transparency. This paper will assess the achievements of the office therein, as well as the limitations inherent in the Ombudsman’s role. The discussion will begin with a brief exposition of the Ombudsman’s mandate, before moving to some preliminary remarks on transparency within the EU legal order. Following this, the Ombudsman’s work in transparency and openness will be presented in two parts: first, the proactive initiatives (including own-initiative inquiries or the adoption of the European Code of Good Administrative Behaviour) and, second, the reactive contribution (namely decisions further to a submission of a complaint). The final part of the discussion will reflect upon the challenges that the Ombudsman is facing when attempting to render the EU administration more transparent and, through this, to increase democracy in the EU.