Per New Zealand Herald, on Feb. 28, 2021, filming began in Dunedin, New Zealand, for The Royal Treatment. Filming took place on "Vogel St in the morning and later across Princes St; a white limousine, fit for a princess, was parked outside the historic and newly renovated Wains Hotel; and a taxi that did not a resemble any Dunedin taxis was parked behind it."

The newspaper also reported that several facades had been placed over local landmarks, such as the Wains Hotel, which received a Victorian-style royal makeover. The Otago Daily Times reported the interior scenes from the film's trailer were shot in Olveston House.

Olveston House was previously owned by businessman, collector, and philanthropist David Theomin, his wife Marie, and their two children, Edward and Dorothy. The historic setting has since been preserved for guided tours — and, apparently, film sets!

Larnach Castle stands in for the royal castle of Lavania. The castle is advertised as "New Zealand's only castle," and the land on which it stands was purchased in 1870 by William James Mudie Larnach, a local politician and businessman. Construction officially began in 1871 and was completed in 1874 when William and his wife moved in. Sadly, after a series of personal and financial setbacks, William died in 1898.

Since 1967 the castle has been privately owned by Barry and Margaret Barker as a tourist attraction.

In early February 2021, Netflix called for extras for Dunedin and South Island people, per Stuff. The article also mentioned The Royal Treatment would film exclusively in Dunedin and Oamaru during February and March with a production crew comprised of locals. Reportedly, the Royal Treatment set was one of the smallest international crews of film and TV in New Zealand at the time.