Hollywood actress Angelina Jolie has worked as a special envoy for the United Nations (UN) Refugee Agency for many years, but the specifics of her trip to Ukraine are unclear.
The video, which shows Jolie signing a piece of paper and waving to the camera, was posted on Facebook by Ukrainian Maya Pidhorodetska and has since had more than 19,000 shares.
Pidhorodetska wrote a post with the video in Ukrainian which, translated by Google, said: "Nothing special. Just Lviv. I just went to have coffee. Just Angelina Jolie.
"Ukraine is simply supported by the whole world."
Lviv, in western Ukraine, has been under attack from the Russian army in recent weeks and earlier this month, a missile attack on the city left at least seven people dead.
In February, Jolie spoke about the war in Ukraine in a post to her 12.7 million Instagram followers.
"My focus along with my @refugees colleagues is that everything possible is done to ensure the protection and basic human rights of those displaced, and refugees in the region.