This book constitutes the refereed proceedings of the 4th International Workshop&nbsp;on Algorithmic Bias in Search and Recommendation,&nbsp;BIAS 2023, held in Dublin, Ireland, in April 2023.<div><br><div>The 10 full papers and 4 short papers included in this book were carefully reviewed and&nbsp;selected from 36 submissions. The present recent research in the following topics: biases exploration and assessment; mitigation strategies against biases; biases in newly emerging domains of application, including healthcare, Wikipedia, and news,&nbsp;novel perspectives; and conceptualizations of biases in the context of generative models and graph neural networks.</div></div>