Yes — there is active women's sumo, though it exists entirely outside the professional Grand Sumo system organized by the Japan Sumo Association.
Amateur women's sumo has official international competitions sanctioned by the International Sumo Federation (IFS). Women compete in weight categories similar to other combat sports. Japan has produced strong women's sumo athletes, and the sport is practiced in many countries.
The professional barrier: The Japan Sumo Association's professional circuit (Grand Sumo) is exclusively male, and this is unlikely to change. The prohibition extends beyond competing — women are not permitted to enter the dohyo (competition ring) at official events, a rule rooted in traditional Shinto beliefs about ritual purity. This rule has caused controversy: in 1990 and 2018, female politicians who had won sumo tournaments were refused permission to enter the dohyo to present prizes.
In 2030, the IOC is considering sumo for potential Olympic inclusion, which would require women's categories. This may eventually influence amateur but not professional sumo.