South Australian Premier Jay Weatherill has vowed to change some of the more than a dozen state laws that discriminate against sexual minorities.

The Law Reform Institute at the University of Adelaide said in a report that as many as 14 pieces of legislation were unfair to lesbian, gay, bisexual, transgender, intersex and queer (LGBTIQ) South Australians.

As an example, it said, the Wills Act treats married couples differently from those who could not legally marry in SA, such as gay people.

Law Reform Institute director John Williams said it was important to end all forms of discrimination.

"There's a whole swag of terminology which has just, in a way, passed us by. The world is a much more diverse place than some of this legislation started life with," he said.

"There's more than 140 pieces of legislation [overall] that have sort of binary notions of male and female, but also there's significant legislation that makes the lives of those LGBTIQ members of our community just difficult."

Mr Weatherill vowed to change some laws immediately to align with contemporary expectations, but said others would take longer to consider.

"Unfortunately, elements of our laws still discriminate ... that's why we asked the [Institute] to review our laws and identify legislation that discriminates against members of our community who identify as LGBTIQ," he said.

"In all, we will immediately begin preparing omnibus legislation that will either modify or repeal aspects of up to 14 different pieces of legislation to ensure they are contemporary."

Mr Weatherill said the Adoption Act was being considered as part of a separate review.