Rihanna also posted a picture of herself playing with a herd of elephants in the street Friday night, with the comment: "They all hail Empress when She walk by."
On the same night, she tweeted a few unprintable comments about what she apparently witnessed at an adult show in one of Phuket's red-light districts.
Saturday's social media postings were devoted to the beach and photographs of the singer in a black bikini on a boat surrounded by turquoise water with limestone cliffs in the distance.
Before leaving Thailand on Sunday, she posted from the airport: "Gave the immigration guy my passport and he handed me this in return without a word. Lol." The Instagram image had a picture of the singer that said "I love Rihanna."
She performed on Sunday in Singapore before her tour heads to Australia and New Zealand.