The 43rd Australasian Combinatorics Conference (43ACC) will be held at The University of Melbourne, Australia, 13-17 December 2021. Researchers in any area of discrete mathematics and its applications are warmly invited to attend this conference and give talks. Contributed talks will be around 20 - 25 minutes in length including time for questions. ACC is the annual conference of the Combinatorial Mathematics Society of Australasia (CMSA), which was called the Australasian Conference on Combinatorial Mathematics and Combinatorial Computing (ACCMCC) from 1989 to 2019. Past and future editions of this international conference can be found at http://combinatorics-australasia.org/conferences.html.