Luigi "Gigi" Segre (8 November 1919 – 28 February 1963) was an Italian automotive designer noted for his business and engineering acumen during his stewardship and ownership of Carrozzeria Ghia (1953–63), one of an Italy's premier automobile design and coachbuilders.

Segre is widely associated with his prominent role in the genesis of the Volkswagen Karmann Ghia – a car that reached a production of nearly a half million, and a car that noted designer Dick Teague called one of the "most beautifully designed products."

Segre began working at his father's construction business, only to have his career and education interrupted by the outbreak of World War II. Stationed in Naples on 8 September 1943, when the armistice was announced, Segre immediately voiced opposition to the German troops occupying the city – and participated in the Four days of Naples. When allied troops arrived, he made himself available to the US command, and after a brief training in Tunisia, parachuting into the Canavese, he became an official liaison between the Office of Strategic Services (OSS) – precursor to the modern CIA – and partisan groups working in the Piedmont. He also worked to repatriate former Italian soldiers from France. It was during this period, Segre had begun to master English and become familiar with the American way of thinking.

Following positive recommendations from the Allied Command in the immediate post-war period, Segre was hired as a manager at Ford, graduated in engineering and subsequently moving to Siata (Società Italiana Auto Trasformazioni Accessori) where he studied automotive design with Giorgio Ambrosini. In a brief racing career, Segre took 1949 and 1950 first place victories in the Mille Miglia Turismo 1100 class (in a Fiat 1100) – with teammate Gino Valenzano (1920–2011).

Segre married Luisa de Berto in 1955 and together they had sons Edmondo (1957-) and Silvio (1959-). Luigi Segre died suddenly and unexpectedly in a Turin clinic at age 43, during convalescence after successful removal of kidney stones. Doctors suspected Segre had contracted a viral infection during a recent business trip to Brazil, but at the time the hypothesis could not be confirmed. He left behind his wife, Luisa, and two sons, at the time 6- and 4-years old. In 1971, Luisa Segre opened a resort, La Meridiana, between Monaco and Portofino, as of 2018 operated by Edmondo Segre and his wife Alessandra.

Before turning thirty, Segre joined Carrozzeria Ghia in 1948, hired by Mario Boano as Commercial Director, then becoming a minority owner. Using his nickname "Gigi," he actively toured Italy, contacting and personally meeting all Ghia's dealers. Orders increased, his income tied to a percentage of orders. As the Carrozzeria's Director of Sales, Segre would leave to consummate a deal estimated at ten million, returning with a contract for thirty million.

Eventually, English-speaking Segre would travel to the United States to meet Chrysler's chief stylist Virgil Exner and CEO K. T. Keller. Segre served as Ghia's interlocutor as Boano did not speak English – leaving Segre to forge strong personal alliances with Exner and Chrysler while leaving Mario Boano in a diminished role within his own company. For Segre, a working alliance with Chrysler provided the valuable opportunity to elevate Carrozzeria Ghia's international stature. Exner in turn was able to quickly see actual prototypes of his studio's work – at a dramatically lower cost (e.g., one tenth to one twentieth) than Chrysler was producing its prototypes. Segre became full owner of Carrozzeria Ghia in 1954, after Mario Boano left over their differences – Boano wanting Ghia to focus on local work and Segre wanting to form international liaisons.

Segre developed contracts with Volkswagen, Renault, Fiat, Volvo and several others to continuously develop their show cars, as well as possible production models and facelifts. In 1953, Segre worked with Renault, when the company chairman, Pierre Lefaucheux, requested Ghia's assistance with the forthcoming Dauphine.