When a member of one of India’s wealthiest families gets married, big-name guests and showstopping pomp and circumstance are nothing unusual. But it’s not every day that the invitees include royalty, business titans, Bollywood luminaries and Rihanna, for three days of a pre-wedding spectacular, months ahead of the actual ceremony.

The lavish festivities that got underway on Friday for Anant Ambani, whose father heads Reliance Industries, have seized public attention in India despite — or perhaps because of — how they underscore gaping inequality in a country that has enjoyed economic growth yet where millions still live in profound poverty.

Mr. Ambani, 28, the younger son of Mukesh Ambani, will welcome the guests at a sprawling venue in the western Indian state of Gujarat, along with his fiancée, Radhika Merchant. Ms. Merchant, 29, comes from a family that owns health care businesses and is trained in Indian classical dance.

The couple started the festivities earlier this week with a community feast: hosting thousands of people from neighboring villages and serving them Gujarati delicacies.

But for the main event starting Friday night, more than 1,000 guests, including some of the world’s richest people, are expected. Notable invitees include Bill Gates, Mark Zuckerberg of Meta and Bob Iger of Walt Disney; present and former prime ministers of Canada, Sweden and Qatar; the king and queen of Bhutan; and Bollywood stars Amitabh Bachchan, Shah Rukh Khan and Madhuri Dixit. Among the luxurious touches planned are chartered flights for the guests and people available to iron their clothes or help apply their makeup.

The guest list is part of the pageantry. Guests are not just (or not even) friends, but attractions in their own right. Apart from enjoying the spectacle, many will appreciate the chance to sidle up to India’s most influential business family at the bar. Mr. Iger’s presence, in particular, seems well timed: Nita Ambani, Mukesh Ambani’s wife, is reportedly poised to become chairwoman of the board of the company created by a merger of Reliance with Walt Disney’s Indian media assets.

There is precedent for extravagant Ambani nuptials. At a ceremony for Anant’s sister in 2018, two former U.S. secretaries of state in attendance, Hillary Clinton and John Kerry, both reportedly danced to bhangra, a type of pop music from India’s Punjab region.

This time, the Ambani family has commissioned female artisans from the region to weave handmade scarves as gifts to the guests and a tribute to Indian heritage. Dozens of specialty chefs will prepare dishes, the estimated number of which ranges from 500 to 2,500, according to some media accounts.

The average annual salary in India is about $2,750, but lavish feasts are a regular part of Indian weddings, even for people of modest means. The Ambanis are splashing out like any other family — though on an entirely different scale.

A video invitation that has gone viral lays out the agenda. Day 1’s theme is “An Evening in Everland,” and the dress code is “elegant cocktail.” On Day Two, “Walk on the Wild Side,” guests are requested to wear animal-print clothing ahead of an evening of dance and music.

Comfortable footwear is suggested on the final day, when guests will tour an animal rescue, rehabilitation and conservation project that is a favorite charitable undertaking of the groom.

That evening, dressed in traditional Indian clothes, guests will witness “Hastakshar,” the signing ceremony between the couple, at a temple.

The actual wedding is not until July. It’s probably going to be fancy too.

Alex Travelli contributed reporting.