Mayor Rahm Emanuel flipped the tree switch at 5 p.m. during the 98th annual tree lighting ceremony in Daley Plaza.
The 55-foot Colorado Spruce comes from the Spangler family in Western Springs. They were also expected to help with the lighting.
ABC7 Chicago's Mike Caplan and Windy City LIVE's Val Warner helped light the tree.
The tree features 5,800 multicolored lights and a five-pointed star perched on the top.
Also Wednesday, Christkindlmarket returned to Daley Plaza. It opens daily at 11 a.m. The traditional German Christmas market will be open through Christmas Eve.