This paper reports on the 45th European Conference on Information Retrieval (ECIR 2023), held in Dublin, Ireland, during April 2--6, 2023. The conference was the largest ECIR ever, and brought together hundreds of researchers from Europe and abroad. For those who like numbers: First, we received 489 submissions in total (including 228 full and 153 short papers) excluding further workshop submissions. Second, the technical program committee consisted of 624 reviewers in total (including 27 chairs, 124 SPC, 473 reviewers) with many serving on multiple tracks. Third, the proceedings necessitated a third volume, and contains a total of 175 papers in 2,151 pages. The rest of this report details the conference program and events. Date: 2--6 April 2023. Website: https://ecir2023.org/.