The pair departed from Fua'amotu International Airport, Tonga, as their 16-day tour continued.
As they walked to their Qantas flight along a path lined with several large handmade tapa mats and children from local schools, the pair stopped at the steps of the plane and thanked Princess Angelika.
“Thank you so much for your hospitality,” Meghan said.
Earlier, the duke and duchess were driven to the Royal Palace for an audience with King Tupou VI and his wife Queen Nanasipau’u.
The couple entered the wooden, whitewashed palace and spent around 15 minutes inside with the royals.
Harry had changed into a suit following his excursion to the rainforest, but Meghan was still in her blue Veronica Beard shirt dress.
The duke and duchess signed a visitors’ book before they left and then posed outside with the king and queen for photographers.
They also shook hands with the Tongan ruler and his wife, with Meghan noticeably curtsying to the queen.