Suu Kyi was pictured smiling as she walked through the airport in the nation's capital, Naypyitaw, flanked by officials, a day after thousands rallied in the city to support her and a prayer ceremony was held in her name.
Demonstrations are planned throughout the coming week, with hearings set for Dec. 10 to 12, and several dozen supporters are also bound for The Hague, in the Netherlands, to cheer Suu Kyi on.
Gambia, a tiny, mainly Muslim West African country, filed a lawsuit in November accusing Buddhist-majority Myanmar of genocide, the most serious international crime, against its Rohingya Muslim minority. During three days of hearings, it will ask the 16-member panel of U.N. judges at the International Criminal Court of Justice to impose "provisional measures" to protect the Rohingya before the case can be heard in full.
More than 730,000 Rohingya fled Myanmar in 2017 after a brutal military-led crackdown the U.N. has said was executed with "genocidal intent" and included mass killings and rape.
Despite international condemnation over the campaign, Suu Kyi, whose government has defended the campaign as a legitimate response to attacks by Rohingya militants, remains overwhelmingly popular at home.