Aluminium alloys are increasingly popular in structural engineering applications because they have high strength, low weight and great durability. However, the mechanical properties of aluminium alloy material may be significantly affected by high temperature. This paper presents a numerical study on the behaviour of aluminium alloy channel section columns at elevated temperatures. A non-linear finite element (FE) model was developed and validated against 27 experimental results at high temperature. The validated FE model was used to conduct an extensive parametric study, in which a total of 360 aluminium alloy channel section columns were generated at elevated temperatures. The key parameters for the parametric study include two types of aluminium alloys (6061-T6 and 6063-T5), three lengths (360 mm, 1000 mm and 2000 mm) of columns and ten temperatures (range from 24 °C to 600 °C). The design strengths were calculated using American, Australia/New Zealand and European Standards and compared with the numerical results generated from parametric study. In addition, a reliability analysis was used to assess the reliability level of the considered design methods.