The analysis of Non-Liquid Matrices (NLMs) can provide key information on many aspects in drug discovery and development. These include but are not limited to drug uptake and distribution, engagement and modulation, and target exposure. A thorough understanding of these aspects is fundamental to the progression of drug development. In many cases, such an understanding can only be achieved through quantitative analysis of NLMs. Such dependence can lead to bottlenecks in the drug development process-as the practices and regulations that govern bioanalysis of conventional liquid matrices typically cannot be directly applied to NLMs. This paper strives to fill this crucial gap. To this end, subject matter experts from across the industry, through the auspices of the AAPS Bioanalytical Community, have combined their collective best practices for NLM bioanalysis in this paper. Certainly, this endeavor came with challenges, the most prominent of which also serves as the impetus for this project, the lack of literature on NLM bioanalysis dealing with different types of NLM, analysis rigor, and best practices to draw from. This paper aims to serve as a comprehensive set of best practices drawn from the experiences of leading scientists across the industry-for NLM bioanalysis in drug development.