They've Irish surnames! They must be Irish, right?! Not so. Check out these superstars you've probably always assumed were Irish American.

Nobody would ever have thought that Barack Obama could possibly have any Irish connection but sure enough, he did. Yet there are many other Americans who may appear to be Irish because of their names but have no connection to the country whatsoever.

Here are the top Americans with Irish names who aren't really Irish at all:

Mickey Rooney

Mickey Rooney, who died on Sunday, April 6, 2014, was the son of Joseph Yule (originally Ewell), born in Glasgow, Scotland. Mickey's given name was Joseph Yule, Jr. He took Mickey Rooney after his mother wanted to call him Mickey Looney to enhance his comedian career.

Hulk Hogan

The famous American wrestler’s real name is Terry Gene Bollea. He was born in Augusta, GA and is of Italian, French, and Panamanian heritage.

John Kerry, US Secretary of State

Kerry is a practicing Catholic from Massachusetts but his family's roots lie in Judaism. His grandfather Fritz Kohn and Fritz's brother Otto were living in Vienna in 1901 when, suffering greatly under the anti-Semitism that prevailed in Europe, Fritz decided to shed his Jewish-sounding name. He dropped a pencil on a map of Ireland and it landed on County Kerry. Fritz changed his name to Frederick Kerry.

Meg Ryan

Known for her famously good lunch alongside Billy Crystal in “When Harry met Sally,” Meg Ryan’s given name is Margaret Mary Emily Anne Hyra. Although she does have some Irish heritage her family name Hyra is Polish.

Julianne Moore

Julianne Moore with that red hair and Irish last name? She’s Scottish. The US actress was born Julie Anne Smith.

She was born to an American father and Scottish mother in California. In 2011, she claimed British citizenship to honor her dead mother.

Al McCoy

The boxing world champion who died in 1966 was born Alexander Rudolph. The champ, who was Jewish, took on the name McCoy so his parents wouldn’t find out about his new career.

Frank Costello

Frank "the Prime Minister" Costello was born Francesco Castiglia. He was an Italian-American crime boss and gangster. He was born in Lauropoli, a mountain village in Calabria, Italy, in 1891, and moved to New York with his family as a young boy.

Lou Costello

The famous comedian of Abbott and Costello fame sounds Irish, but were Lou Costello's ancestors Irish or Italian?

Originally named Louis Francis Cristillo he changed his name out of admiration for the actress Dolores Costello, who in the 1930s helped him with his career.

Danny Thomas

An American nightclub comedian and television and film actor and producer, whose career spanned five decades, his name was originally Amos Muzyad Yakhoob Kairouz. Born in Michigan his parents were Maronite Catholic immigrants from Lebanon. In 1940 he came up with the pseudonym "Danny Thomas" (after two of his brothers) and was often mistaken for Irish.

Joe Malone

Italian American politician in Massachusetts who won terms as State Treasurer in the 1990s and tried to run for Congress. Now a successful businessman, most Bostonian Irish assumed he was of their heritage and he never sought to dissuade them, but he was one of seven children of Italian American parents.

* Originally published in 2014.