Sweeny began karting in 2017, competing until 2021. In his time in karts, Sweeny most notably won the 2020 New South Wales and ACT state titles in the Senior Performance Light class. The same year, Sweeny also made his car racing debut in the
Toyota Gazoo Racing Australia 86 Series as a member of the
Erebus Academy. Remaining in the series the following two years, Sweeny scored three podiums in the series as he scored a best reason finish of fifth in 2022. In 2022, Sweeny also made his debut in TCR competition, joining HMO Customer Racing to race in
TCR Australia. In his first season in the series, Sweeny scored his maiden series in race two of the first
Bathurst round, before taking his second win at the same venue in November to end the year fifth in points, as the rookie of the year. The following year, Sweeny remained with HMO Customer Racing for his sophomore season in
TCR Australia. Starting off the season with two wins at
Symmons Plains, before winning race three at
Winton, as well as races two and three at
Sandown en route to a third-place points finish. Having spent most of 2024 on the sidelines, Sweeny made a one-off appearance in the
Winton round of the RX-8 Cup Australia for Maisie Place Motorsport, in which he finished second in races three and four. Following that, Sweeny joined Image Racing to compete in the second
Bathurst round of the
Super3 Series. In his only round of the season, Sweeny finished second in race two and third in race two. Remaining under the Supercars Championship support bill for the following year, Sweeny joined
Blanchard Racing Team as he stepped up to the
Super2 Series following Super3's demise. In his rookie year in the series, Sweeny scored a best result of third in race one at
Queensland Raceway, as well as two other top 10 results en route to a 13th-place points finish. Sweeny returned to
Blanchard Racing Team and the
Super2 Series for 2026. ==Karting record==