Linseed (Linum usitatissimum), also known as flaxseed, is a nutrient-dense oilseed widely recognized for its health benefits and industrial uses. For consumer safety, legal compliance, and commercial acceptability, linseed and goods produced from it must be labeled with precision and high quality. This chapter provides an in-depth analysis of the quality and labeling standards associated with linseed and its products, beginning with an overview of its nutritional significance, industrial applications, and grading criteria based on physical and chemical properties such as moisture content, oil composition, and purity. It further examines the established quality and labeling requirements for raw and processed linseed products, including oil, flour, and supplements, alongside regulatory frameworks from international bodies like Codex Alimentarius and country-specific guidelines from key markets such as the USA and the European Union. Additionally, it discusses labeling elements, including nutritional declarations, allergen warnings, and organic certifications, to enhance consumer transparency and confidence. The chapter also addresses potential contaminants and adulterants, such as pesticide residues, heavy metals, and microbial impurities, which can affect the safety and overall quality of linseed products.