Los Angeles World Airports Executive Director Gina Marie Lindsey announced the news during a 1 p.m. news conference Saturday.
"Terminal 3 is now open and fully operational," said Lindsey.
No flights were being allowed to depart from the terminal Saturday morning. Passengers were being bused to different terminals to catch their flights.
Officials said those who left belongings behind at Terminal 3 were be able to retrieve items starting Saturday at 10 a.m. at ticket counters.
An unidentified traveler told Eyewitness News that she and ten other travelers shared a bag of peanuts Friday night. Another man said he was able to buy food after a kind stranger gave him money.
"I was sitting there and I started eating and when I opened my yogurt, I heard the gunshots," said traveler Becky Jauregui. "I had my wallet on my lap, and I jumped up, my wallet fell on the floor. I started running, everybody was running and I just hid under a chair. I went back and got my purse but my wallet was still on my seat."
Saturday night, the reopened terminal was servicing a huge backlog of passengers. Among them was Hollywood resident Stephen Lynch, who was traveling for almost two days trying to get home.
"Exhausted. Just exhausted. I mean sad about the whole thing. One crazy 23-year-old could interrupt 1,500 flights and thousands of people," said Lynch.
While new luggage is arriving from flights just into the airport, the big challenge that remains is the large amount of bags abandoned by passengers as they fled the airport during the shooting.
"It was simply the most crazy thing I've ever seen in my life," said John Sliwa of Seattle.
Sliwa sat on the tarmac for hours and was told to leave his bag behind.
"They deplaned us and said 'get out of the airport.' I spent a lot of time on the beach there yesterday. I went over to the Goodwill and bought some swimming trunks and hit the beach," said Sliwa.
As investigators searched the terminal early Saturday, passengers were kept away from their bags. Despite all the headaches, passengers are cognizant at the end of the day, all this is just stuff.
"It was an experience I'll never forget for the rest of my days. God bless all the people that got lucky enough to get out of that whole thing," said Sliwa.
On Friday, Paul Anthony Ciancia pulled an AR-15 assault rifle out of a bag and opened fire at a screening checkpoint around 9:20 a.m.
A TSA officer was killed in the shooting. He was identified by a TSA official as 39-year-old Gerardo I. Hernandez. He was declared dead upon arrival at Harbor-UCLA Medical Center, with gunshot wounds to the chest and abdomen. Hernandez had been with the TSA since 2010 and is the first TSA officer to be killed in the line of duty in the 12-year history of the agency.
Friends and neighbors remembered the Los Angeles man as a doting father of two and a good neighbor who went door-to-door warning neighbors to be careful after his home in the Porter Ranch area of Los Angeles was burglarized.
On Saturday, a wreath was placed in the spot where Hernandez was fatally shot. All TSA officers at LAX are now wearing black bands over their badges.
Two other TSA officers were shot and injured as passengers ducked for cover, hid in bathrooms and ran for their lives. They are expected to survive. Authorities say an additional two people were injured, but their injuries may be from trying to flee from the scene.
LAX police located the suspect, and there was an exchange of gunfire. The 23-year-old suspect remains hospitalized in critical condition. Eyewitness News has learned that he was shot four times, including in the mouth and leg.
Los Angeles Airport Police Chief Patrick Gannon said "within seconds we had our officers chasing the suspect through the terminal."
The motive for the attack remains unknown.
Ciancia's father in New Jersey had called authorities for help in finding his son after the young man sent one of his siblings a text message about committing suicide, Pennsville Police Chief Allen Cummings said.
Law enforcement sources say Ciancia, a U.S. citizen, carried a note with him that suggested he was anti-government and expected to die in the airport shootout.
People who knew Ciancia said they were shocked that he was the alleged gunman.
The shooting disrupted hundreds of flights across the U.S. Friday, many of which were held on the ground at LAX or not allowed to take off for Los Angeles from other airports.
Throughout the day, an estimated 1,550 scheduled arriving and departing flights with around 167,000 passengers were affected, according to the airport. That included 86 arriving flights that were diverted to other airports.
Los Angeles International Airport is the nation's third-busiest airport. Terminal 3 is the last terminal on the north side of LAX. Airlines that operate out of the terminal include Allegiant Air, Frontier, JetBlue, Spirit and Virgin America.
TSA Administrator John Pistole is scheduled to meet with his workforce in Los Angeles Saturday. Pistole sent his employees a note following the shooting, commending them for their professionalism.
"During the course of the day, many of you were involved in working under enormously stressful and emotional conditions. I thank you for your continued dedication to our mission."
The note from Pistole also went on to praise the TSA employees for their support for each other.
The Associated Press contributed to this report.