She was portrayed by Isla Fisher in the 2013 film adaptation.
Sometime prior to the events of the story a financially unsatisfied Myrtle met George Wilson and the two bonded fairly quickly. Exited at the prospect at a chance to climb her way up the social ladder Myrtle winded up marrying Wilson who much to her dismay was much less interested than she was in gaining great financial wealth. Luckily for her though the immensely wealthy aristocrat Tom Buchanan took an interest in Myrtle and the two began seeing each other behind George's back.
The Great Gatsby
Before being seen Myrtle was notorious for continuously phoning the Buchanan residence at inconvenient times much to the annoyance of Tom. This unfortunately for him made his current affair far more obvious to the eyes of his wife Daisy of whom he was now constantly at odds with thanks to Myrtle's persistence. Myrtle is first physically seen when Tom takes his old friend Nick Carraway into town to visit her and head to party in the flat he rented out for her. At the party Myrtle's sister Catherine shows up among several others and a wild party ensues. That night after having sex with Tom Myrtle begins talking about Daisy much to Tom's frustration, she then proceeds to stubbornly say her name over and over again in spite of Tom's growing frustrations and warnings before Tom eventually has enough and slaps Myrtle across the face so hard that he breaks her nose and knocks her off of her feet.
Overtime George grows more suspicious of Myrtle and even arranges a getaway for both of them thanks to his growing suspicions of her adultery and eventually he gets into a massive argument with her regarding her loyalty to him climaxing when she eventually breaks free from his hold and elbows his face temporarily subduing him. She then sees Jay Gatsby's yellow car outside of the mechanic's office and rushes out towards it due to her mistaking it for Tom's car before being struck down and killed by Daisy Buchanan who was unable to react quickly enough to avoid her.
Following Myrtle's death Tom shows a surprising amount of remorse for the loss however he uses the circumstances to his advantage by convincing Wilson that Gatsby purposefully killed Myrtle as he was the one she was having an affair with. This leaves a grief stricken George to kill Gatsby and soon after himself with a handgun.
Myrtle was a very ambitious and headstrong individual who was unhappy with her current position both financially and romantically. She was also a playful, fun loving and wild party animal who longed to live a life of glamour and hedonism. Myrtle was also shown to be quite oblivious to other people however and rather selfish to a certain degree.