The name Lainey is a diminutive form of the name Laina, which itself is a variant of the Hebrew name Lena. The name Lena is derived from the Greek word "lene" meaning "light" or "bright". It is believed that the name Lainey originated in the early 19th century as a nickname or pet form of Laina.

The earliest recorded use of the name Lainey can be traced back to the United States in the late 19th century. One of the earliest known individuals with this name was Lainey Beighle, who was born in Pennsylvania in 1885. Another early bearer of the name was Lainey Goss, an American educator and suffragist who lived from 1875 to 1949.

In the 20th century, the name Lainey gained some popularity, particularly in English-speaking countries. One notable figure was Lainey Vines, an American actress who appeared in several films and television shows in the 1950s and 1960s. Another individual named Lainey was Lainey Gossett, an American singer and songwriter who released several albums in the 1970s and 1980s.

One of the most famous individuals named Lainey was Lainey Keogh, an Irish author and playwright who lived from 1909 to 1987. She is best known for her novels and plays that explored the lives of working-class Irish families and their struggles.

Another notable person with the name Lainey was Lainey Spears, an American artist and sculptor who lived from 1925 to 2008. Her works, which often featured abstract forms and nature-inspired themes, were exhibited in galleries throughout the United States.

While the name Lainey has its roots in the Hebrew and Greek languages, it has gained popularity across various cultures and regions over time. Its association with brightness and light has likely contributed to its enduring appeal as a given name.