Professor Aidan Sims' work in theoretical mathematics has generated enduring research activity, solved significant open problems, and established unexpected connections across mathematics. Among key contributions, he built higher-rank graph C*-algebras from infancy into a major research field; established a long-sought "Rosetta Stone" between Leavitt path algebras and graph operator algebras; computed the exact nuclear dimension of all Kirchberg algebras; and extended the celebrated Boyle-Tomiyama theorem to arbitrary dynamical systems. Professor Sims was an invited speaker at the 2015 Abel Symposium, the 2016 AustMS Medallist, and is the Incoming President of the Australian Mathematical Society.