Limited information is available on accumulation, distribution, and remobilisation of dry matter (DM) and nutrients in cotton (Gossypium hirsutum L.) under the interaction of nutrient management and genotype. We conducted a 2-year field experiment to study the impacts of phosphorus (P) treatments (0, 16.5, 33, 66, 132 and 198 kg P ha^–1) on growth and P absorption, allocation and remobilisation in three cotton genotypes. At maturity, the maximum DM and P content allocation to seeds were 20.7% and 62.3%, respectively. Compared with the anthesis stage, leaf DM and P content at maturity significantly decreased by 46.3% and 73.6%, respectively; thus, seed P content was mainly contributed by leaves. Compared with the control (nil P), optimal P fertilisation (33–66 kg P ha^–1) increased leaf DM and P content at anthesis by 21.2% and 40.8%, promoted P translocation from leaves to seeds by 43%, and improved lint yield at maturity by 22.8%. At anthesis and maturity, the DM and P content of the entire plant, and lint and seed yields were higher in genotypes XLZ57 and XLZ19 than in XLZ13. Suitable P doses increase DM and P accumulation and yield, and improve source–sink relationships of DM and P in cotton.