Korra first met Lin Beifong when she arrived in Republic City and was arrested for the damage she caused while fighting a group of members from the Triple Threat Triad. Lin was not impressed with Korra about her being the Avatar and was not willing to let her off easy until Tenzin came into the room and convinced her to drop the charges. Later, when Tarrlok held a gala in Korra's honor, Lin showed up but still insisted that Korra did nothing to deserve it.
After a threat from Amon, the council was about to cancel the pro-bending finals until Lin barged into the room and convinced them to just up the security. Korra was thankful for this but Lin just passed by while ignoring her. Korra asked Tenzin what her grudge was about and finally realized that Tenzin had dated Lin before dumping her for Pema. Later, Lin watched Korra during her pro-bending match and was surprised that a peaceful guy like Aang was reincarnated into her. Tenzin insisted that Lin could get along with Korra if she just gave her a chance. Later, the Equalists attacked and Lin managed to save Korra from falling twice. Korra thanked her and Lin told her not to worry about it.
After the tournament, Korra found out that Hiroshi Sato was an Equalist and Lin assisted her in the investigation. They were later caught in a trap and Lin sustained injuries which caused her to be hospitalized. Korra was eventually captured by Tarrlok although Amon was framed for it. Lin heard that Korra had been captured while laying in the hospital and listening to the radio. She left the hospital and busted Korra's friends out of jail so that they could go look for her. They eventually found her and Lin asked her where everybody was and how she escaped.
After Korra rested and recovered, she finally sat down and told Lin and Tenzin everything. Later that day, the Equalists managed to take over Republic City. Korra and Team Avatar went into hiding while Lin left with Tenzin's family. However, the Equalists were gaining on them so Lin turned back to halt them and was captured. Amon offered to let Lin keep her bending if she told him where Korra was but Lin refused so he took away her bending.
When Korra was rescuing Tenzin, she asked where Lin was but he said he didn't know. After Amon was defeated, Lin found out that Korra had also lost her bending and comforted her, saying that she could not believe that Amon got her too. Lin accompanied Korra to the South Pole while Katara attempted to heal her. Katara came out and said that she could not restore Korra's bending. Lin pleaded that there must be a way but Katara had already tried everything. Korra eventually regained her bending and was able to restore Lin's bending as well. Lin thanked Korra for this.
Korra and Lin did not interact much during the Unalaq crisis. When Korra returned to Republic City, Lin sarcastically congratulated her for starting a war and complained about a peace protest that it caused. Following Harmonic Convergence, Korra and president Raiko got into a heated argument until Lin stepped between them and ended the argument.
Lin eventually found out that Zaheer and his group escaped from prison. Lin personally went to Ba Sing Se to retrieve Lin since she felt that Korra was in immediate danger. Lin insisted that Korra returned to Republic City where she could protect her, but Korra refused to leave because the Earth Queen was holding a group of airbenders hostage. Lin helped her rescue the airbenders so that she would leave. Korra later learned of another airbender in Zaofu and Lin reluctantly followed her there.
Lin requested that Korra not tell anybody that Lin was there and Korra complied until the truth-seer Aiwei forced the truth out of her. Korra found out about Lin's half-sister and found her to be nice. Things later got heated when Lin yelled at her shy niece Opal and Korra told her that she would be cranky and alone for the rest of her life. This caused Lin to cry. Lin later yelled at some guards for idling about while there were terrorists after Korra. Korra later checked in on Lin and found her stumbling about but Lin insisted that she was fine.
The Red Lotus managed to sneak into Zaofu at night and attempted to kidnap Korra. Luckily, everybody around grouped up and put a stop to it. Lin swooped down and held Korra while the others stopped the Red Lotus. Lin questioned Su as to how they got in. Korra wanted to chase after Aiwei who was the traitor but Lin insisted that she return to Republic City. Su got Korra to agree with her but helped her sneak out to chase Aiwei. Lin was furious with Su for this and went after Korra.
The Red Lotus eventually captured all of the airbenders at the Northern Air Temple and demanded that Korra turn herself in or they wipe them out. Korra announced her decision to turn herself in and Lin immediately protested, but Korra had already made up her mind. When it turned out that they were double-crossing her, Lin and Su jumped in while attempting to rescue her and nearly succeeded until Zaheer unlocked his ability to fly and flew off with her. Later, Lin witnessed as Korra was dying from the poison and Zaheer cackled that it was too late. Lin watched in worry as Su metalbended the poison out of her body. Three weeks later, the two went to Jinora's mastery ceremony and earthbended a wheelchair-bound Korra up a flight of stairs. Korra was in a very weak state but Lin put a hand on her shoulder and told her to hang in there.
Fans have shipped Korra and Lin together ever since the two started to get along after the pro-bending tournament. People started to ship them further when Lin left the hospital and later sacrificed her bending to protect Korra. When Lin was kneeling before Korra to have her bending restored, a lot of fans remarked that it almost looked like Lin was proposing to Korra. Even though Korra was already dating Mako by then, they soon broke up in Book Two. Despite the age gap, a lot of fans ship them together and a lot fan fiction in the hurt/comfort area has been written about them.
- Lin and Korra's past life Aang supposedly got along famously.