The establishment of a new National Commission on Women comes amid warnings that women from the Tamil minority face widespread sexual exploitation by officials in their own community as well as from the military.
The commission will have powers of prosecution, said the government in a statement.
Sri Lanka's former president Chandrika Kumaratunga said last week that women faced sexual abuse from local officials, with those widowed during the 37-year conflict particularly at risk.
Prosecutions of military personnel or officials for sex crimes are rare in Sri Lanka, although four soldiers were jailed for 25 years for the gang-rape of a young Tamil mother in 2010, a year after the war ended.