Her paternal grandfather, Akiba Hornstein, was a Jewish emigrant from Lithuania who changed his name to Giffords to avoid anti-Semitism in the United States.

She received a Bachelor of Arts degree in Sociology and Latin American History from Scripps College in California in 1993;[4] and spent a year as a Fulbright Scholar in Chihuahua, Mexico.

In 1996, she became president and CEO of El Campo Tire Warehouses, a local chain of auto service centers founded by her grandfather.

In early 2005, Giffords observed that "the 2004 election took its toll on our bipartisan coalition" and that as a result "a number of significant problems will receive far less attention than they deserve."

Her Republican opponent in the general election was Randy Graf, a conservative former state senator known for his enforcement-only position on immigration and illegal aliens.

[24] In her first month in office, Giffords voted in favor of increased federal funding for embryonic stem-cell research;[25] raising the minimum wage;[26] endorsing the 9/11 Commission recommendations;[26] new rules for the House of Representatives targeting ethical issues;[27] and the repeal of $14 billion of subsidies to big oil companies, in favor of renewable energy subsidies and the founding of the Strategic Renewable Energy Reserve.

[30] She voted for the contentious May 2007 Iraq Emergency Supplemental Spending bill, saying, "I cannot, in good conscience, allow the military to run out of money while American servicemen and women are being attacked every day".

On April 21, 2007 (the same day Giffords hosted her third "Congress on Your Corner" in Tucson, Arizona) she also spoke at the Sahuaro Girl Scout Council Annual Meeting.

[36][37] On January 8, 2011, Giffords was shot in the head[38] outside a Safeway grocery store in Casas Adobes, Arizona, a suburban area northwest of Tucson, during her first "Congress on Your Corner" (a public opportunity for constituents to speak directly with their representatives)[39] gathering of the year.

[38] On the same day doctors performed emergency surgery to extract skull fragments and a small amount of necrotic tissue from her brain.

[57] Doctors who first treated Giffords said the bullet entered the back of her head and exited through the front of her skull, but physicians later concluded that it had traveled in the opposite direction.

[58] Upon receiving a call from a staffer about Giffords's injury, her husband Mark Kelly and his daughters flew in a friend's aircraft directly from Houston to Tucson.

[61] Nancy Pelosi (the House minority leader) shared that Giffords's husband Mark Kelly had acknowledged that there was a "rough road ahead" in her recovery, but that he was encouraged by her responsiveness,[62] including her ability to signal with her hand and move both arms.

[63] U.S. Army neurologist Geoffrey Ling of the Uniformed Services University in Bethesda, Maryland, was sent to Tucson to consult on Giffords's condition.

[65] On January 12, President Barack Obama visited Giffords at the medical center and publicly stated in an evening memorial ceremony that she had "opened her eyes for the first time" that day.

[67] As Giffords's status improved, by mid-January she began simple physical therapy,[68] including sitting up with the assistance of hospital staff and moving her legs upon command.

[68][60] On January 15, surgeons performed a tracheotomy, replacing the ventilator tube with a smaller one inserted through Giffords's throat to assist independent breathing.

[69][70] Ophthalmologist Lynn Polonski surgically repaired Giffords's damaged eye socket,[71] with additional reconstructive surgery to follow.

[78] In late April, Giffords's doctors reported that her physical, cognitive, and language production abilities had improved significantly, placing her in the top 5 percent of patients recovering from similar injuries.

[85] Giffords underwent cranioplasty surgery on May 18, 2011, to replace the part of her skull that had been removed in January to permit her brain to swell after the gunshot to her head.

[90] Having learned the French horn as a child, she picked it up again as part of her music therapy and in August 2020 spoke about that experience in a speech endorsing Joe Biden's presidential bid.

[92] A Giffords spokesman, Mark Kimble, stated in August 2011 that the congresswoman was walking without a cane and was writing left-handed, as she did not have full use of her right side.

Appearing on the floor of the House, after the last bill she sponsored was brought to a vote and unanimously passed, Giffords was lauded by members of Congress and the majority and minority leaders who spoke in tribute to her strength and accomplishment in an unusual farewell ceremony.

[103] For the 2020 Democratic National Convention, Giffords delivered a speech supporting presidential nominee Joe Biden and urging action on gun control.

In 2013, shortly after the Sandy Hook Elementary School shooting, Giffords and her husband founded the nonprofit and super PAC Americans for Responsible Solutions (ARS) to support pro-gun control candidates.

[123] On August 1, 2008, she wrote to congressional leaders regarding tax credits that were set to expire, arguing that failure to extend the scheme would be extremely harmful to the renewable energy industry "just as it is beginning to take off".

However, she stopped short of supporting the law itself, saying that it "does nothing to secure our border" and that it "stands in direct contradiction to our past and, as a result, threatens our future".

The bill was over $100 million less than Giffords fought for, but she said, "This funding signals a stronger federal commitment to protect those Americans who live and work near the border.

In 2008, before being shot, Giffords opposed prohibitions in Washington, D.C., on the possession of handguns in the home and having usable firearms there, signing an amicus brief with the U.S. Supreme Court in District of Columbia v. Heller to support its overturn.

[131] In January 2013, Giffords and her husband Mark Kelly started a political action committee called Americans for Responsible Solutions whose mission was to promote gun-control legislation with elected officials and the general public.