Harold Allen Ramis (/ˈreɪmɪs/ RAY-miss; November 21, 1944 – February 24, 2014) was an American actor, comedian, and filmmaker. His film acting roles include Egon Spengler in Ghostbusters (1984) and Ghostbusters II (1989), and as Russell Ziskey in Stripes (1981); he also co-wrote those films. As a director, his films include the comedies Caddyshack (1980), National Lampoon's Vacation (1983), Groundhog Day (1993), Analyze This (1999) and Analyze That (2002). Ramis was the original head writer of the television series SCTV, on which he also performed, as well as a co-writer of Groundhog Day and National Lampoon's Animal House (1978). The final film that he wrote, produced, directed, and acted in was Year One (2009).

Ramis's films influenced subsequent generations of comedians, comedy writers and actors. Filmmakers and actors including Jay Roach, Jake Kasdan, Adam Sandler, Judd Apatow, and Peter and Bobby Farrelly have listed his films among their favorites. Along with Danny Rubin, he won the BAFTA Award for Best Original Screenplay for Groundhog Day.

Ramis was born on November 21, 1944, in Chicago, Illinois, the son of Ruth (née Cokee) (1919–2001) and Nathan Ramis (1915–2009), who owned the Ace Food & Liquor Mart on the city's West Side. Ramis had a Jewish upbringing. In his adult life, he did not practice any religion. He graduated from Stephen K. Hayt Elementary School in June 1958 and Nicholas Senn High School in 1962, both Chicago public schools, and in 1966 from Washington University in St. Louis, Missouri, where he was a member of the Alpha Xi chapter of Zeta Beta Tau fraternity.

Afterward, Ramis worked in a mental institution in St. Louis for seven months. He later said of his time working there that it:

…prepared me well for when I went out to Hollywood to work with actors. People laugh when I say that, but it was actually very good training. And not just with actors; it was good training for just living in the world. It's knowing how to deal with people who might be reacting in a way that's connected to anxiety or grief or fear or rage. As a director, you're dealing with that constantly with actors. But if I were a businessman, I'd probably be applying those same principles to that line of work.

Ramis began writing parodic plays in college, saying years later, "In my heart, I felt I was a combination of Groucho and Harpo Marx, of Groucho using his wit as a weapon against the upper classes, and of Harpo's antic charm and the fact that he was oddly sexy—he grabs women, pulls their skirts off, and gets away with it." He avoided the Vietnam War military draft by taking methamphetamine to fail his draft physical.

Following his work in St. Louis, Ramis returned to Chicago, where by 1968, he was a substitute teacher at schools serving the inner-city Robert Taylor Homes public housing development. He also became associated with the guerrilla television collective TVTV, headed by his college friend Michael Shamberg, and wrote freelance for the Chicago Daily News. "Michael Shamberg, right out of college, had started freelancing for newspapers and got on as a stringer for a local paper, and I thought, 'Well, if Michael can do that, I can do that.' I wrote a spec piece and submitted it to the Chicago Daily News, the Arts & Leisure section, and they started giving me assignments [for] entertainment features." Additionally, Ramis had begun studying and performing with Chicago's Second City improvisational comedy troupe.

Ramis's newspaper writing led to him becoming joke editor at Playboy magazine. "I called…just cold and said I had written several pieces freelance and did they have any openings. And they happened to have their entry-level job, party jokes editor, open. He liked my stuff and he gave me a stack of jokes that readers had sent in and asked me to rewrite them. I had been in Second City in the workshops already and Michael Shamberg and I had written comedy shows in college." Ramis was eventually promoted to associate editor.