The boys' names that became girls' names

In 1902, Leslie was the 85th most popular boys' name in America. One boy in 529 got it. One girl in 7,575 did. It stayed a boys' name through the First World War, the twenties and the Depression. In 1945 it was one boy in 693 and one girl in 790. In 1946 the girls passed it, one in 754 against one in 772, and they never gave it back. By 1969 Leslie was the 64th most popular girls' name in the country. The boys' Leslie left the boys' top 1,000 after 1997 and has not been seen since.

Everyone knows a name like this. What we wanted to know was how many there are, when each one crossed, and what happens to the boys' version afterwards. So we went through 129 years of American records and counted.

Twenty-eight names

We hold the American top 1,000 for boys and for girls, for every year from 1880 to 2008, as each name's share of the babies of that sex. A name is on this list if boys got it more often than girls for at least five years, at a rate of at least one boy in 10,000, and girls then got it more often in every year but two from the crossing to 2008, reaching at least one girl in 2,000 along the way. The crossing is the first year of the girls' run. Twenty-eight names pass.

“Best year” is the year the name had its biggest share of boys, or of girls, with its rank among boys' or girls' names that year. The last column is the last year the boys' version was anywhere in the boys' top 1,000. The series stops in 2008, so a name still there in 2008 may have left since.

Some of these were never much of a boys' name. Beverly reached one boy in 7,874 at its best. Lindsey one in 7,194. Others were proper boys' names. Sidney was the 80th boys' name in 1912. Leslie was 85th in 1902. Taylor was 52nd in 1992. Which brings us to the thing we did not expect.

The boys do not let go

Taylor crossed in 1990. Its best year as a boys' name was 1992, two years after the girls had passed it. That is not a one-off. In 15 of the 28 names, the boys' version had its best year ever after the girls had already taken it. Kelly crossed in 1957 and peaked for boys in 1967, at 102nd. Ashley crossed in 1964 and peaked for boys in 1980, the year it was the 40th girls' name. Morgan crossed in 1980 and peaked for boys in 1995. Riley crossed in 2002 and peaked for boys in 2006, at 101st.

So the crossing does not stop parents giving the name to boys. Not at first. What it does is start a clock. Seventeen of the 28 had lost their boys' version from the top 1,000 by 2008, and for those seventeen the gap between the crossing and the boys' last year was 13 years at the shortest, 88 at the longest, and 44 in the middle. Lynn crossed in 1942 and the boys' Lynn was last in the top 1,000 in 1986. Kim crossed in 1955 and was gone for boys after 1985. Leslie took 51 years. Billie took 88.

Two generations, give or take. The boys named Leslie in 1946 were grandfathers before the country stopped naming boys Leslie at all.

Ashley, which was barely a boys' name

Ashley is the one everyone reaches for, and in America it is not really a story about a boys' name at all. In 1885 it was given to one boy in 8,928, the 521st boys' name. It never got bigger than that until the girls arrived. The girls' Ashley enters the top 1,000 in 1964, at 771st. In 1980 it was 40th. In 1985 it was 2nd. In 1991 and 1992 it was the most popular girls' name in the United States, and at its best, in 1987, one girl in 34 was an Ashley. The boys' Ashley rode along behind, peaking in 1980 at 282nd, and was gone from the boys' top 1,000 after 1994. Ashley did not so much cross as get carried off.

Kelly is the cleaner case. From 1885 to 1949 the boys' Kelly never got above one boy in 3,500 or below one in 13,200. Then in the 1950s both versions took off at once. In 1955 it was 204th for boys and 380th for girls. In 1957 the girls passed it. By 1960 it was 52nd for girls and 128th for boys, and in 1977 it was the tenth girls' name in the country. The boys' Kelly kept climbing for a decade after the crossing, peaked at 102nd in 1967, and was last in the top 1,000 in 2002. Forty-five years after it crossed.

It only goes one way

We ran the same test in the other direction: girls' names that became boys' names. The rule finds four. Donnie and Toby were never given to more than about one girl in 5,000, so they hardly count. That leaves Ashton, which was a girls' name in the 1980s, one girl in 1,934 at its best in 1986, and more common for boys from 1998, and Angel, an ordinary boys' name in Spanish-speaking families, which has been more common for boys than girls since 1986. Two against 28. A name can go from boys to girls. It almost never comes back.

Britain has not crossed

All of that is America. England and Wales publish every name given to three or more babies, split by sex, and the 2025 file tells a different story for the names that crossed most recently. The American figures here are from 2010, the most recent American file we hold that splits a name by sex.

Riley is a girls' name in America. 5,506 girls to 3,606 boys in 2010, and 48th in our catalogue now. In England and Wales it is the 83rd most popular boys' name, 619 boys to 270 girls. Morgan went to 4,043 American girls and 494 boys. Here, 128 boys and 65 girls. Taylor went to 5,858 girls and 947 boys there, and to 76 boys and 20 girls here. Sidney was given to 247 boys in England and Wales last year and 25 girls.

And Ashley, the most popular girls' name in America in 1991, went to 49 boys and 25 girls in England and Wales in 2025. Those are small numbers and we would not build much on them alone. The 2024 file says the same, 36 boys and 23 girls, so we will say it. In Britain, Ashley is still a boys' name.

Where Britain has crossed, it has crossed the same way. Avery, Sydney, Aubrey and Addison are girls' names in both countries. Leslie is now five boys a year in England and Wales and not enough girls to make the list. Kelly is fourteen girls and no boys. Nothing on the list is a girls' name in Britain and a boys' name in America. The traffic between the two countries runs in one direction, and America is ahead.

Two you will not find

Vivian and Lindsay are the names people ask about, and neither is in the table. Vivian was already more common for girls than boys in 1880, the first year of the American records, one girl in 4,444 to one boy in 16,949. If it crossed, it crossed before anyone was counting. Lindsay was never given to more than one American boy in 5,780, and the girls' Lindsay came from nowhere: not in the top 1,000 in 1970, 71st in 1980, 40th in 1985. In America, Lindsay did not become a girls' name. It started as one. Lindsey, with an e, did cross, in 1974, and it is in the table.

Britain may tell a different story for both. Our English and Welsh series only starts in 2024, so we cannot see it, and we are not going to guess.

What we can see is this. If you are naming a boy Riley or Morgan in England and Wales, you are in the majority. In America you are not, and in every crossed name whose story the American file has finished telling, the boys' version faded out. Slowly. The boys named Kelly in 1967 never knew.