She debuted as a teenager in a local band named Carnival. She studied music and acting in Göteborg, where she met her husband, Andreas Werliin, with whom she formed the Wildbirds & Peacedrums duo. The band played concerts with Lykke Li and received jazz industry awards.
Other projects involving Mariam Wallentin include a solo experiment – Mariam the Believer, Fire!Orchestra, Gothenburg String Theory and Nuiversum.