%X In this letter, we investigate a fluid antenna system (FAS)-assisted downlink non-orthogonal multiple access (NOMA) for short-packet communications. The base station (BS) adopts a single fixed antenna, while both the central user (CU) and the cell-edge user (CEU) are equipped with a FAS. Each FAS comprises N flexible positions (also known as ports), linked to N arbitrarily correlated Rayleigh fading channels. We derive expressions for the average block error rate (BLER) of the FAS-assisted NOMA system and provide asymptotic BLER expressions. We determine that the diversity order for CU and CEU is N , indicating that the system performance can be considerably improved by increasing N . Simulation results validate the great performance of FAS. %O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. %I Institute of Electrical and Electronics Engineers (IEEE) %L discovery10188057 %K Block error rate (BLER); flexible-position antenna; fluid antenna system (FAS); non-orthogonal multiple access (NOMA); short-packet communication %J IEEE Transactions on Vehicular Technology %P 1-6 %D 2024 %A Jianchao Zheng %A Tuo Wu %A Xiazhi Lai %A Cunhua Pan %A Maged Elkashlan %A Kai-Kit Wong %T FAS-assisted NOMA Short-Packet Communication Systems