Like Cinderella arriving at the palace, a bejeweled tiara always gets noticed, whether it is worn at the Oscars, the Met Gala, or an exclusive state occasion requiring a ball gown and satin gloves.

“Over the last five years worldwide, we’ve probably sold over 80 tiaras,” Kristian Spofforth, head of jewelry at Sotheby’s London, said during a recent video interview from his New Bond Street office. “They are popular things and there are more tiaras out there than you would think. People are fascinated by them.”

So much so, he said, that an average of 1,000 people a day visited Sotheby’s recent showcase of more than 50 royal and aristocratic tiaras.

Today, plenty of jewelers are offering tiaras, whether as a belle epoque antique or a contemporary custom-made design.

One of the items shown at Sotheby’s tiara showcase sold while on display, Mr. Spofforth said: The Opium Poppy Crown, a design from this year of voluptuous brass blossoms on a gold frame by the British jeweler Christopher Thompson Royds, was priced at 1,800 pounds ($2,200). Two more Sotheby’s clients have since asked the jeweler to recreate it for them, Mr. Spofforth said.

The majority of tiara sales are concentrated among Chinese consumers, a sector that is on track to become the world’s largest luxury goods market by 2025, according to the consulting firm Bain & Company in a report in January.

“I’d say maybe even as much as three-quarters of the interests we have in our tiaras have come from the Chinese market,” said Guy Burton, director of the jeweler Hancocks London, operating since 1849 and now specializing in high-end antique jewelry.

The company’s Anglesey tiara — a £900,000 glamazon from 1890 set with more than 100 carats of old European and mine-cut diamonds — was among those for sale at the Sotheby’s exhibition. According to Mr. Burton, it received some inquiries but no offers during the show.

With tiaras, Mr. Burton said, “weddings are the most functional and popular use of them” and since last spring, Hancocks has also been quietly renting its inventory of antique tiaras for nuptials and other special occasions.

Some people just want to try one on.

Beginning in 2013, the Beaumont Etiquette consultancy offered a $599 “Duchess Effect” course at the Plaza Hotel in New York that included a “tiara try-on” segment of both costume and diamond-studded styles.

The class has been on hold during the coronavirus pandemic, but the Beaumont Etiquette founder Myka Meier said she hoped it would resume in the autumn. An $74 online version began last month, drawing 40 to 50 people per day, Ms. Meier said.

“Prepandemic, people would come from all over the world to take the class, it would sell out every time and we’d have to close the wait list at 100 guests,” she said by phone last month in London, where she attended events tied to the Queen’s Platinum Jubilee.

As a service to clients looking to acquire a tiara for a special event, Ms. Meier said that she and her team had also sourced headpieces through a network that includes the British costume-jewelry designer Andrew Prince, who created items for “Downton Abbey” television and film productions.

The impact of such programs, including Netflix’s “Bridgerton” and “The Crown,” alongside headlines surrounding the royal family is palpable, Ms. Meier said: “There’s been a rush of everything royal — tiara etiquette questions, and clients asking, ‘How can I purchase one?’”

If a diamond tiara seems like an extravagant novelty worn on the rarest of occasions, jewelers point out that many designs have mechanisms that allow them to convert into a necklace or be taken apart to form brooches and hair pins.

That versatility is central to their current appeal.

The British jeweler Theo Fennell, who moved his atelier this spring to the Chelsea Barracks development in London, approaches his bespoke tiara and diadem commissions with multifunctional uses in mind. With prices starting at £6,000, he said he tried to make each design “as adaptable as possible; what we’re doing is being more of a mechanic, engineering something that will allow the piece to be worn a few more times if a moment comes up.”

At Garrard, the British jeweler that made the blue sapphire and diamond engagement ring for Lady Diana Spencer, offers a line of made-to-order tiaras that all have a detachable pendant (prices start at £75,000).

The antique-jewelry retailer Fred Leighton, a red-carpet mainstay based in New York, recently had four 19th-century tiaras for sale, including a $100,000 one with five detachable star motifs that has appeared during multiple awards shows. Most recently, the jewel was worn by the singer Billie Eilish at the Academy Awards in March — but not in her hair. Ms. Eilish’s stylist Dena Giannini worked with the Fred Leighton chief creative officer Rebecca Selva to temporarily dismantle the jewel so that the stars could be worn as rings and earrings.

“I think that there is tremendous interest in tiaras because both in the bridal arena and in the way we dress to go out, people feel free to express their creativity and individual style,” Ms. Selva said on a video call.

Even so, there are some ground rules for tiara-wearing, according to Ms. Meier. For starters, they were traditionally worn only by married women and never before 6 p.m.

“I wouldn’t wear a tiara unless it was stated on the invitation,” said Ms. Meier, who attended a Platinum Jubilee celebration with an invitation that called for the wearing of “tiaras and medals.”

But times and rules change. The rapper Kendrick Lamar wore a jeweled headpiece shaped like a crown of thorns from Tiffany & Company during his set at the Glastonbury 2022 music festival in England. And the actress Ruth Negga was single in 2017 when she wore a ruby tiara created in collaboration with her stylist Karla Welch and the Los Angeles-based jewelry designer Irene Neuwirth. The piece sold that same year during a trunk show at the Naples, Fla., jewelry store Marissa Collections. “It went to an amazing collector of ours who is actually in her early 90s now,” Ms. Neuwirth said. “She’s fabulous and she wears it every time I see her.”

Ms. Neuwirth shares Ms. Selva’s view that wearing a tiara is not about indulging a princess fantasy but about standing out in a crowd and expressing your individual style. “It’s for the woman who wants to take a risk, the cool kid who wants to express her creativity in a bolder way,” she said. “I think it’s a strong power move.”