In Hollywood, people expect certain traits of nuns:
- Dress Code: They will wear the full "penguin suit" habit most of the time (though there are a few exceptions; e.g., an all-white habit). Young nuns-in-training might wear just the headpiece or veil (that's why it's called "Taking the Veil"), to let the audience know they're still in the pupal stage. (Postulants are rank beginners: they become novices after about six months in basic training.)
- Temperament: They will either be terrifying spectres of discipline, able to strike fear into even the toughest men, wielding yardsticks like samurai wield katanas, or sweet and nurturing with overtones of forbidden sexuality. Young novices may be fresh-faced girls-next-door; old Mothers or Novice Mistresses may be sweetly wise and saintly, setting an example reminding you of why you wanted to join up in the first place.
- Age Group: They will either be old and super-traditional or young and naive (most of them old).
- Names: They will often have "Sister Mary..." (referring to Mary, the "Holy Mother") as part of their name (but not always). Many of them will have a male saint's name.
- Nun vs. sister: Most of them will referred to as nuns even though most orders in which the women are out of their community are of religious sisters, with nuns living in cloister.
- The monstrous Sociopathic Hero Marv, of Sin City, claims to have feared and respected the nuns at his school. One of the possible reasons why he mostly never hits women.
- Sister Act at once plays this straight and averts it, which is the source of most of the comedy. Incidentally, Whoopi Goldberg's character is given the name of "Sister Mary Clarence" while in the convent.
- Sister Mary Stigmata ("The Penguin") in The Blues Brothers plays the "elderly, scary disciplinarian with a yardstick" role almost straight, except for the fact that she moves like she's on wheels.
- The two nuns in Doubt fit the two different temperaments pretty well.
- But their order wore bonnets instead of the stereotypical squarish cornettes and veils over a tight-fitting coif cap. They are the Sisters of Charity of St. Vincent de Paul in New York and were founded by St. Elizabeth Ann Seton, the first American saint.
- The nun in Dead Man Walking, considering this film is based on a true story, is a subversion in dress with her wearing regular clothes with only a gold cross lapel pin to denote her affiliation. When a priest calls her out on that, she quotes the Pope who ruled that the full habit is not necessary anymore as long as a nun wears something distinctive to mark her calling.
- In The Song of Bernadette the Sisters of Charity and Christian Instruction fit this exactly, but they're a real order and it's a matter of historical record. The film producers sent a request to the mother-house at Nevers, France for a copy of the pattern for the exact habit worn at the time Bernadette was there. In fact, The Song of Bernadette is almost certainly one of the Trope Codifiers for this trope.
- The nuns in The Nun's Story are the Sisters of Charity of Jesus and Mary, and they also fit this exactly, right down to the awesomely wise Mother Superior played by Dame Edith Evans. This film is another candidate for this trope's Trope Codifier, alongside The Song of Bernadette and The Sound of Music.
- The Sound of Music, of course, may just be the most popular depiction of nuns in film, and ticks practically every box on the list.
- In Mr. Smith Goes to Washington, the orphan boys who cheer Smith's proposed boys' camp bill from the gallery are escorted by Daughters of Charity of St. Vincent de Paul. The "Flying Nun" cornettes are unmistakable.
- Nuns appear in the series Father Ted on various occasions, varying from strict disciplinarians to sweet/tempting.
- Pushing Daisies had nuns in full habits, but in keeping with its setting in a candy-colored Retro Universe, the habits were blue and white instead of black and white. (The Sisters of Mary of the Eucharist and Sisters of Life really do wear blue and white.)
- In an early Season 2 episode of The A-Team, the A-Team traveled to Ecuador to help a group of nuns (including Face's former One True Love from college) in full stereotypical-looking habits protect their mission from a bunch of nuns. Of course, the full habits helped Face and Murdock sneak into the mission to do reconnaissance work. Also, Face's old flame had taken the name "Sister Theresa" and she fit into the second temperament.
- One episode of House fully subverts this trope when a nun is found to be dying from a strange allergy. The convent she lives in only use the full habit on special occasions; the other nuns who visit her are dressed realistically in conservative dresses with headpieces. The sick nun herself was found to have had an abortion and used an old form of birth control that left a piece of copper in her body (which she was allergic to).
- Sister Peter Marie in Oz doesn't wear the habit, but seems to generally follow the rest of the trope (although being rather jaded due to being around the worst humanity has to offer).
- Averted with Sister Peg of Law & Order: Special Victims Unit. She looks to be about middle-aged, doesn't wear the habit at all, and is neither naive nor excessively strict—which is reasonable for a nun who mostly works on aiding prostitutes to keep them safe and healthy.
- Surprisingly averted on Once Upon a Time. The nuns, who were faeries in the magical world, wear plain dresses and overcoats rather than habits.
- Averted in Call the Midwife. For one thing, the nuns in question are Anglican, not Catholic. For another, although they do wear habits, the habits are Fifties-esque (when the show is set) and dark blue, not black—although the more iatrophobic residents of Poplar will still call them "penguins" when they're being derisive. And their names are Sister Julienne, Sister Evangelina, Sister Bernadette, and Sister Monica Joan — not a Mary in sight (although they are all saints' names). And finally, besides being nuns, they are midwives and nurses with full modern training—arguably, they are nurses first and nuns second.
- Strongly averted in Brides of Christ. Diane and Veronica's postulancy and later life as sisters is shown with great accuracy and detail. Halfway through the series, their order begins to modernise with the newer habits and less cumbersome rosaries.
- In the The Mary Tyler Moore Show episode, "Almost a Nun's Story", Georgette considers joining the convent. When a nun in contemporary dress shows up to counsel Georgette, Ted doesn't realize she's a nun and tries to pick her up, leading to a comical conversation where she obliquely refers to "the other man in her life" (i.e. God) and Ted misses every cue.
- The scary disciplinarian nuns tend to be a staple for comedians who grew up going to Catholic school.