Semenya is challenging proposals by the International Association of Athletics Federations (IAAF) that aim to restrict female athletes' testosterone levels.
In a statement, the Lausanne-based court said the week-long hearing, which wrapped up on Friday, was "one of the most pivotal CAS cases" the tribunal has heard.
The three-panel will announce their verdict "on or before March 26," the court said.
The IAAF is seeking to force so-called "hyperandrogenic" athletes or those with "differences of sexual development" (DSD) to seek treatment to lower their testosterone levels below a prescribed amount if they wish to continue competing as women.
The athletics governing body has argued the moves are necessary to create a "level playing field" for other female athletes.
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But Semenya has a wide group of vocal backers, including South Africa's government, who have accused the IAAF of seeking to perpetrate serious human rights violations on female athletes.
South Africa's sports minister Tokozile Xasa, who flew into Switzerland this week to back Semenya and her legal team, accused the IAAF of pursuing "the violation of women's bodies."
Semenya is not the only athlete potentially affected by the new rules - the two athletes who finished behind her in the Rio Olympics 800m, Francine Niyonsaba of Burundi and Kenya's Margaret Wambui, have also faced questions about their testosterone levels.