• Lied to her mother and the LAPD that she could not identify Jason McCormack, because she planned to killing him out of revenge. ("Collision")
• Faked being a prisoner of the tailies to Sawyer, Michael and Jin to see if they were others
• Had sex with Sawyer to get his gun. ("Two for the Road")

Charlie

• Attempted to con Lucy to get money for heroin. ("Homecoming")
• Lied to Claire by telling her he didn't know heroin was hidden in the Virgin Mary statues. ("The 23rd Psalm")
• Aided and abetted Sawyer in a con job to get back at Locke. ("The Long Con")
• Allowed Desmond to think he was taking Charlie's place on the suicide mission before knocking Desmond out with the oar. ("Greatest Hits")

Hurley

• Concealed food from the Swan food locker. ("One of Them")
• Lied to Sawyer, telling him the other survivors would vote to banish him if he wasn't nice to them. ("Left Behind")
• Acted as though Locke had left him behind to help Locke capture Sayid, Kate, and Miles. ("The Economist")
• Lied to the public along with the other Oceanic Six about what really happened on the island and during the crash. ("There's No Place Like Home, Parts 2 & 3")
• Lied to Walt by indicating that his father was still alive on the Island. ("There's No Place Like Home, Parts 2 & 3")

Jack

• Played along with Michael's betrayal, even after figuring it out, to help Michael retrieve Walt. ("Live Together, Die Alone")
• Gave Michael an unloaded weapon to maintain the appearance of trust. ("Live Together, Die Alone")
• Agreed to operate on Ben to save his life; instead, made Ben a hostage. ("I Do")  ("Not in Portland")
• Agreed with Locke to fabricate a lie, with the other Oceanic Six, about the island and the crash. ("There's No Place Like Home, Parts 2 & 3")

Kate

• Has several false identities.
• Pretended she doesn't know how to use a gun. ("Pilot, Part 2"); ("Whatever the Case May Be")
• First falsely claimed to be the owner of the Halliburton case, then lied to Sawyer that she doesn't want the Halliburton case. ("Whatever the Case May Be")
• Attempted to conceal the key of the Halliburton case from Jack when they recovered it from Edward Mars' body. ("Whatever the Case May Be")
• Deceived her partners in the bank robbery about the goal of the robbery, then turned on them. ("Whatever the Case May Be")
• Talked Sun into poisoning Jin in an attempt to get herself on the raft; additionally, deceived Sun into thinking she was nobly only trying to help her. ("Born to Run")
• Helped Cassidy Phillips escape a Jewelry con gone bad by saying her father ran a store and pretending to buy a "real" necklace. Later, she and Cassidy conceived a plan to evade the police so Kate could visit her mother. ("Left Behind")
• Married Kevin under the false name Monica, then drugged him and left because of her shame at deceiving him. ("I Do")
• Drugged Jack to make him sleep. ("The Greater Good")
• Pretended that she was being chased by the Others when she was, in fact, working with the Others to lure Keamy and his men into a trap. ("There's No Place Like Home, Parts 2 & 3")
• Lied to the public along with the other Oceanic Six about what really happened on the island and during the crash. ("There's No Place Like Home, Parts 2 & 3")

Michael

• Pretended to have found the Others, when in fact he was captured by the Others, as part of an agreement to retrieve Walt. ("Two for the Road")  ("?")  ("Three Minutes")
• Murdered Ana Lucia and Libby, allowing Ben to escape, as part of that same agreement. ("Two for the Road")
• Shot himself to place blame on Ben. ("Two for the Road")
• Led Jack, Kate, Sawyer and Hurley into an ambush as part of the agreement. ("Live Together, Die Alone")
• Used a fake name to get a job on the freighter and hid his true motives for being there. ("Meet Kevin Johnson")

Sawyer

• Is a professional con man.
• The name "Sawyer" is a false identity; his real name is James Ford. Sawyer's namesake, Anthony Cooper (who went by "Tom Sawyer"), seduced his mother and took all their money. ("Confidence Man")
• Conned Kate into giving him a kiss by pretending to know where Shannon's inhaler was (even under threat of torture). ("Confidence Man")
• Conned the Losties to gain possession of the guns. ("The Long Con")
• Used Cassidy in a long con, despite falling in love with her. ("The Long Con")
• Conned Munson into letting Sawyer help Munson hide his money; instead, revealed the location of the money to Warden Harris and Agent Freedman. ("Every Man for Himself")

Sayid

• Under pressure from Alyssa Cole and Robbie Hewitt to cooperate with their sting operation, agreed to fool Essam into thinking he was trustworthy enough to join the terrorist cell Essam was a member of. ("The Greater Good")
• Successfully prevented Essam's suicide bombing and recovered the explosives, but the realization of his betrayal led Essam to commit suicide. ("The Greater Good")
• Helped Nadia escape by killing Omar and injuring himself. ("Solitary")
• Tricked Frank into believing their deal entailed bringing both Charlotte and Miles back from Locke's camp ("The Economist")
• Conned Elsa by posing as her boyfriend to gain access to her boss ("The Economist")
• Lied to the public along with the other Oceanic Six about what really happened on the island and during the crash. ("There's No Place Like Home, Parts 2 & 3")

Shannon

• Convinced Boone that her boyfriend Bryan was beating her so that Boone would pay off Bryan to leave her, and they could split the money. But her plan backfired when Bryan took the money and left. ("Hearts and Minds")
• Re-established her connection to Boone, her stepbrother, by sleeping with him. ("Hearts and Minds")
• Feigned interest in Charlie so that he'd catch a fish for her. ("Walkabout")

Sun

• Pretended not to speak English so that Jin wouldn't find out where she learned it. ("Pilot, Part 1" to "House of the Rising Sun")
• Tried to poison Jin in an attempt to keep him from leaving on the raft. ("Born to Run")
• Had an affair during her English lessons, and told Jin about neither. ("The Glass Ballerina")
• Lied to Jin about why Sayid was making the signal fire so large, but got caught. ("The Glass Ballerina")
• Lied to her father about breaking a statue causing a maid to be fired. ("The Glass Ballerina")
• Planned to leave Jin at the airport and escaping to America. ("House of the Rising Sun")
• Lied to the public about Jin's fate. ("Ji Yeon")
• Lied to the public along with the other Oceanic Six about what really happened on the island and during the crash. ("There's No Place Like Home, Parts 2 & 3")
• Lied to Frank about trusting Ben. ("Namaste")

Walt

• Snuck away from his father to take knife-throwing lessons from Locke. ("Special")
• Set the first raft on fire to keep Michael from leaving the Island. ("...In Translation")

Nikki and Paulo

• Pretended to work for/care about Howard L. Zukerman, but then murdered (poisoned) him for $8 million dollars in diamonds. ("Exposé")
• Knew about the drug smugglers' plane and The Pearl before anyone else, but didn't say anything. ("Exposé")
• "Corvette" learns her boss is really the mysterious underworld figure "The Cobra" on the Exposé TV show. ("Exposé")

• Conned James Ford's parents under the name Tom Sawyer.
• Used Locke's mother to con him into giving away his kidney.
• Is a professional con man.
• Faked his own death to escape his creditors.
• Used Locke again in a money-transfer scam.
• Failed at conning Mrs. Talbot in a wedding con.

Cassidy

• Fledgling con woman, trained by Sawyer as part of a long con.
• Began by convincing people at gas stations to buy fake jewelry.
• Conned the authorities into revealing themselves by impersonating Kate.

Eddie Colburn

• Undercover police agent who pretended to be a hitchhiker drifter to befriend Locke.
• Secretly operated a sting to uncover Jan and Mike's marijuana-growing operation.

Dr. Je-Guy Kim

• Told Jin and Sun while they were together in his doctor's office that Sun was incurably infertile due to advanced endometriosis.
• Later accosts Sun when she is on the street alone to tell her that he had lied and Jin was the infertile one.
  • Claims that he couldn't tell him, for fear that an employee of Mr. Paik would want retribution if he gave him such news.
• Unknown motivations, and unknown which version was a lie at this point.

Hibbs

• Professional Con-man.
• Worked the Tampa Job with Sawyer.
• Conned Sawyer into killing Frank Duckett by convincing him that Duckett was the real "Sawyer".

Kelvin

• Led Sayid to believe he couldn't speak Arabic so that Sayid would torture Tariq.
• Got Desmond to live with him in the Swan for years and believe in the Sickness, when he himself did not.
• During this time, secretly fixed Desmond's boat (the Elizabeth), in the hopes of escaping the Island and leaving Desmond to push the button.

Richard Malkin

• Originally read Claire's fortune as a psychic, and told her that her baby was in great danger if she did not raise it herself.
• Later gave her the option of meeting with a mysterious couple in L.A. who wanted to adopt the baby and give her money
  • Gave Claire the tickets to get on Flight 815.
• When he met Eko he told him he was not psychic, but pretended to earn a living.
• Unknown motivations, and unknown which version was a lie at this point.

Sam Austen

• Always knew that Kate was not his biological daughter, but let her believe otherwise.

• Took great lengths to appear as primitives to the Losties.
  • Tom's fake beard.
  • Dirty clothes, later revealed to be costumes.
  • Fishing village with a fake hatch door.

Ben

• Convinced most of his people (except for Richard Alpert) that he was born on the Island. ("The Man Behind the Curtain")
• Posed as Henry Gale when captured by the Losties. ("One of Them")
• Set up an elaborate plan that included using Michael to lure Jack, Kate and Sawyer into an ambush. ("Exposé")
  • As a part of the plan, Jack would eventually be convinced to treat Ben's medical condition.
• Sent spies to infiltrate the Losties. ("A Tale of Two Cities")
  • Ethan to report on the Mid-Section Survivors.
  • Goodwin to report on the Tail-Section Survivors.
• Attempted to manipulate Jack, Kate and Sawyer (during captivity) toward unknown ends.
  • Used Juliet's resemblance to Jack's ex-wife to manipulate him.
  • Pushed Kate and Sawyer into a situation where their emotions for each other would likely come out in the open.
• Tricked Sawyer into believing they had implanted a pacemaker in his body that would cause his heart to explode. ("Every Man for Himself")
• Manipulated Locke into following through on his plan to blow up the submarine by making him think that he didn't want it to happen. ("The Man from Tallahassee")
• Told Jack that the others were going to kill Jin, Sayid, and Bernard if he didn't give up the satellite phone. ("Through the Looking Glass")
• Told Alexandra that her mother was dead. ("The Man from Tallahassee")
• Told Locke that he had no idea why Charles Widmore wanted the island, but later revealed that he did know. ("The Other Woman")
• Told Jack that he had not spoken to Locke, yet Ben was actually the one who killed Locke. ("Because You Left")
• Sarcastically told Jack that his mother taught him to read, even though she had died in childbirth. ("316")
• Originally claimed his reason for visiting the Monster had nothing to do with Alex's death. ("Dead Is Dead")
• Admitted to Locke that he had never met, seen, or even spoken to Jacob. ("The Incident, Parts 1 & 2")

Ethan

• Pretended to be a crash survivor to infiltrate the group on Ben's orders.

Goodwin

• Pretended to be a tail-section survivor to report on them.

Juliet

• Took part in Ben's plan to "break" Jack, using her own resemblance to his ex-wife Sarah.
• Gave Jack a speech about the importance of saving Ben's life, while simultaneously playing him a video of herself holding cue cards asking Jack to play along but then kill Ben during the surgery. ("The Cost of Living")
• Attempted to manipulate Kate into thinking they were "in it together" by handcuffing herself to her and putting her out in the jungle. ("One of Us")
• Agreed to infiltrate the survivors for Ben and collect information on the pregnant women among them. ("One of Us")
• Double-crossed Ben and told Jack about the planned raid on the beach camp by the Others. ("Greatest Hits")

Mikhail

• Pretended to be the last surviving member of the DHARMA Initiative when he was actually an Other. ("Enter 77")
• Pretended to be walking away innocently after offering medical aid to Naomi when he had actually stolen the satellite phone. ("D.O.C.")

Jacob

• Told Sayid he was lost in Los Angeles to lure him away from being hit by the car that killed Nadia. ("The Incident, Parts 1 & 2")

• Deceived Ben, Sun, Richard, and all of the Others into thinking he was John Locke, tricking them into taking him to Jacob. ("The Incident, Parts 1 & 2")
• Persuaded Ben to stab Jacob convincing him that he was the cause of his fall from grace.