Miko was born in Łódź, Poland, the daughter of actors Grażyna Dyląg and Aleksander Mikołajczak. She grew up in Warsaw, where she studied to be a ballerina. An Americanchoreographer invited her to study in New York City on a scholarship, and she traveled there with her mother on her 15th birthday.
Miko's American film debut was in Coyote Ugly in 2000. In addition, she appeared in three episodes of HBO's Golden Globe and Emmy Award-winning Deadwood, and in The Killers' music video for Mr Brightside (2004). She also appears in the video for The Killers' single "Miss Atomic Bomb" (2012), which is related to "Mr Brightside". Miko broke her foot in the process of the video shoot. In 2010, Miko appeared in the big-budget remake Clash of the Titans as Athena. She was also in a supporting role as an acrobat named Raia in the short lived television series The Cape. Miko appeared in Billy Idol's music video for Can't Break Me Down (2014).
Miko supports green politics and keeps a video blog to talk about her current concerns. Miko was ranked #48 on Maxim's Hot 100 Women of 2001 list.