This two-volume set LNCS 13185 and 13186 constitutes the refereed proceedings of the 44th European Conference on IR Research, ECIR 2022, held in April 2022, due to the COVID-19 pandemic. The 35 full papers presented together with 11 reproducibility papers, 13 CLEF lab descriptions papers, 12 doctoral consortium papers, 5 workshop abstracts, and 4 tutorials abstracts were carefully reviewed and selected from 395 submissions. Chapters “Leveraging Customer Reviews for E-commerce Query Generation” and “End to End Neural Retrieval for Patent Prior Art Search” are available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.