Guidi has born in Foligno and studied piano from a very young age; he pursued it as his sole vocation. His primary teacher through his school and into conservatory was Ramberto Ciammarughi. By attending summer seminars, he was noticed by Rava, who recruited him for one of his now famous "Under 21" groups. Guidi recorded two live albums with this band in 2006 and 2009 for the Editoriale l'Espresso label. He also appeared on two of the trumpeter's ECM albums, Tribe in 2009 and On the Dance Floor in 2012. In addition, he has been a sideman on recordings by saxophonist Mauro Negri, guitarist Roberto Cecchetto, and drummers Tommaso Cappellato and Fabrizio Sferra. He has also been a member of Gianluca Petrella's Cosmic Band and appeared on two of their recordings.

Guidi released his debut album as a leader at the age of 21 with the trio date Tomorrow Never Knows on Venus in 2006, and followed it with a series of acclaimed recordings on Cam Jazz. The first two were self-titled quartet sessions in 2007 and 2008, respectively. In 2010, he released his debut big-band offering, The Unknown Rebel Band, modeled on the influences of Charlie Haden's Liberation Music Orchestra, the Freedom Now Suite band of Max Roach, and the Carla Bley Big Band. His first New York recording with Petrella, drummer Gerald Cleaver, bassist Thomas Morgan, and saxophonist Michael Blake, entitled We Don't Live Here Anymore, was issued in 2011. That same year Guidi signed with ECM. His debut for the label, City of Broken Dreams, was a trio date, recorded with Morgan and longstanding drummer João Lobo. The album was released in June of 2013. In 2015, Guidi returned with yet another trio effort for ECM, This Is the Day. ~ Thom Jurek