Both Giffords and her husband, retired astronaut Mark Kelley, will participate in the event at the University of Arizona .
"Congresswoman Giffords wanted to be back in Tucson for this very emotional weekend," said Pia Carusone, Giffords' chief of staff, in a statement. "She felt it was important to be in her hometown with her family, staff members and a few close friends."
The vigil is one of dozens of events taking place in Tucson this weekend to observe the tragedy.
Along with the six who died in the mass shooting, 13 others were injured, including Giffords. The congresswoman has been undergoing extensive physical and speech therapy for the past year.