Inga Marie Arvad Petersen (6 October 1913 – 12 December 1973) was a Danish-American journalist who was a guest of Adolf Hitler at the 1936 Summer Olympics and also had a romantic relationship with John F. Kennedy in 1941 and 1942.

Secret U.S. investigations uncovered no such evidence, and her past did not harm her professional life or social standing in the United States.

She was a motion picture writer for Metro-Goldwyn-Mayer in 1945[2] and a Hollywood gossip columnist,[3] and from the late 1940s until her death, she was the wife of wealthy cowboy actor and military officer Tim McCoy.

[3] Arvad had scooped her colleagues earlier by reporting that Hermann Göring was soon to marry German actress Emmy Sonnemann.

"[4] Arvad was Hitler's guest at the 1936 Summer Olympics, which led to her being investigated by the FBI in America as a potential spy.

A photograph of her with Hitler surfaced, and the FBI followed her, finding out that she was dating an American ensign, John F. Kennedy, son of the former U.S. ambassador to Britain.

In November 1941, while John F. Kennedy served as an ensign in the U.S. Navy's Office of Naval Intelligence, he and Arvad began a romantic relationship.

When the FBI discovered that the "Ensign Jack" who had been visiting Arvad was, in fact, John F. Kennedy, they extended their investigation through wiretaps.

[9] Kennedy's superior officer, Captain Seymour A. D. Hunter, said that the U.S. Navy viewed Arvad as similar to Mata Hari.

Arvad accepted but then broke off the engagement because of a compliment Hitler once paid her as being "the perfect Nordic beauty" and the effect it might have on Boothby's political career.

Arvad commented that she despised Hitler's policies and only saw him on the two occasions of her interviews; however, the English press made much of her audience with him and Boothby was soon to be seeking re-election.

McCoy and Arvad resided on a 127-acre (0.51 km2) estate in Bucks County, Pennsylvania named Dolington Manor, also known as the Benjamin Taylor Homestead.