A cufflink (also cuff link or cuff-link) is a decorative fastener worn by men and women to fasten the two sides of the cuff on a dress shirt or blouse.

The forerunner of today’s shirt first appeared in the early-16th century, its ruffled wristband finished with small openings on either side that tied together with "cuff strings." Although cuff strings would remain popular well into the nineteenth century, it was during the reign of Louis XIV that shirt sleeves started to be fastened with boutons de manchette, or "sleeve buttons," typically identical pairs of coloured glass buttons joined together by a short, linked chain.

By 1715, simple, paste-glass buttons had given way to pairs of two, decoratively painted or jeweled studs, typically diamonds, connected by ornate gold links.

Hence was born the cuff "link", whether simple glass buttons or gilded and bejeweled studs.

Cufflinks are designed only for use with shirts which have buttonholes on both sides but no buttons. These may be either single or double-length ("French") cuffs, and may be worn either "kissing," with the ends pinched together, or "barrel-style," with one end overlapping the other. The "barrel-style" was popularized by a famous 19th century entertainer and clown, Dan Rice; however, "kissing" cuffs are usually preferred.

Sir James Paul McCartney, MBE, Hon RAM, FRCM (born 18 June 1942) is an English musician, singer-songwriter and composer. Formerly of the Beatles (1960–1970) and Wings (1971–1981), he has been described by Guinness World Records as "The Most Successful Composer and Recording Artist of All Time", with 60 gold discs and sales of over 100 million albums and 100 million singles. With John Lennon, George Harrison, and Ringo Starr, he gained worldwide fame as a member of the Beatles, and with Lennon formed one of the most celebrated songwriting partnerships of the 20th century. After leaving the Beatles, he began a solo career and later formed the band Wings with his first wife, Linda Eastman, and singer-songwriter Denny Laine.

According to the BBC, his Beatles song "Yesterday" has been covered by over 2,200 artists—more than any other song. Wings' 1977 release, "Mull of Kintyre", became one of the best-selling singles ever in the UK, and he is "the most successful songwriter" in UK chart history, according to Guinness. As a songwriter or co-writer, he is included on thirty-one number one titles on the Billboard Hot 100, and as of 2012 he has sold over 15.5 million RIAA certified units in the United States.