“The Sixth International Workshop on Differential Algebra and Related Topics” was held in Beijing from August 10 to August 14, 2015.  The workshop offered an opportunity for participants to present original research, to learn of research progress and new developments, and to exchange ideas and views on differential algebra and related topics. The topics of this workshop included but was not limited to algebraic differential and difference equations, differential and difference dimension theory, differential and difference Galois theory, exterior differential and integrable systems, integro-differential algebras and differential Rota-Baxter algebras, analysis, combinatorics and number theory related to differential algebra, polynomial vector fields, Rota-Baxter algebra and applications, computational differential and difference algebras (characteristic sets, closed-form solutions, factorization etc), applications of differential and difference algebras (control theory, physics, chemistry, biology etc). There were about 60 participants, among which 30 of them were from US, UK, Germany, Austria, Spain, Russia, Argentina, Columbia, Iran and so on. The workshop consisted of 3 plenary talks and 25 invited talks.