The strand, which is expected to fetch between £2,000 and £3,000, was given to hairdresser Betty Glasgow in the mid-60s, along with a note reading: "To Betty, lots of love and hair from John Lennon xx."
Glasgow worked as a stylist on the Beatles' movies Hard Day’s Night and Help.
She said of the band: "It was great fun working with the boys on the films. They were always together in a group and having a laugh.
"My job was to keep their hair in order as the film was made over three months, so their trademark, mop-top haircuts had to be regularly trimmed."
The lock of hair is part of the Betty Glasgow Collection of Beatles and Film Memorabilia, which will be sold at Gorringes in Worthing on December 12.