The builders, teachers, and performers behind the form.

Anna Preminger is the founder, director, lead performer, and primary instructor of Improv Theater Israel (Teatron HaImprov), established in Tel Aviv in 2007, and is widely credited with introducing long-form improvisation to Israel as a sustained institutional practice. She trained at the People's Improv Theater, Magnet Theater, and Annoyance Theater in New York and at iO Theater in Chicago, and studied directly with Keith Johnstone, before returning to Israel to establish the country's first and leading improvisation school and ensemble. Improv Theater Israel performs regularly at Habima (Israel's national theater) and Tzavta Theater in Tel Aviv, and Preminger organizes the Tel Aviv International Improv Festival, which by 2022 had reached at least four editions.

Cale Bain is a Canadian-born improviser, director, educator, and academic based in Sydney, Australia, who has been performing and teaching improvisational comedy since 1988. He trained through the Second City Theatre Company in Toronto before relocating to Australia, where he became Director of Training at Impro Australia and co-founded Improv Theatre Sydney. He served as improv director for Foxtel's Australian adaptation of Whose Line Is It Anyway? and launched Sydney's first longform improv show, Full Body Contact No Love Tennis, which ran for nearly a decade. He holds a PhD in humour, journalism and discourse from the University of Technology Sydney, where he has conducted grant-funded applied improv research with refugee communities and university students.

Charna Halpern (born 1952) is the Chicago producer, teacher, and institution-builder who co-founded ImprovOlympic with Del Close in 1981 and built it into iO Theater, the central Chicago home of long-form improvisation for four decades. Working first in David Shepherd's competition-based framework and then in sustained partnership with Close, Halpern provided the organizational structure, training curriculum, and institutional continuity that transformed the Harold from a workshop experiment into the dominant form in American long-form improv. She co-authored Truth in Comedy (1994) with Close and Kim Howard Johnson, trained Tina Fey, Amy Poehler, Chris Farley, and Mike Myers, and facilitated the team pairings that launched the Upright Citizens Brigade.

Richard Chudnow, known as Dick Chudnow, is a Milwaukee-born comedy performer and producer who co-founded the Kentucky Fried Theater comedy troupe at the University of Wisconsin-Madison with Jim Abrahams and David and Jerry Zucker, and subsequently founded ComedySportz in Milwaukee in September 1984, establishing a franchised competitive short-form improv format that has grown to more than 25 locations across the United States and internationally. ComedySportz adapted Keith Johnstone's Theatresports competitive structure into a family-friendly American sports-themed format, developing a national franchise network through the Comedy League of America.

Doug Diefenbach is a Chicago-based improviser, theater founder, and nonprofit communications professional who in 1997 founded The Playground Improv Comedy Theater in Chicago as the city's first nonprofit cooperative improv theater. Trained at ImprovOlympic under Charna Halpern and Del Close's long-form tradition, he organized The Playground as a member-governed institution in which approximately 140 actor-members participate in governance, performance, and instruction on a volunteer basis, creating an institutional model distinct from the commercial structures of Second City and iO. The Playground has operated continuously since 1997 and has remained active into the 2020s.

Dudley Riggs, born January 18, 1932, in Little Rock, Arkansas, and died September 22, 2020, at age 88, was a fifth-generation circus and vaudeville performer who founded the Instant Theater Company in New York City in approximately 1954 and subsequently established the Brave New Workshop in Minneapolis, Minnesota, in 1961, the theatre that is widely recognized as the longest-running sketch and improvisational comedy theater in the United States, predating The Second City by one year. Riggs brought the format he called audience-input instant theater from circus-derived vaudeville traditions to the upper Midwest, sustaining the Brave New Workshop for 39 years before selling it in 1997. He is the author of Flying Funny: My Life Without a Net (University of Minnesota Press, 2017).

Gary Austin, born October 18, 1941, in Duncan, Oklahoma, and died April 1, 2017, in Los Angeles, California, at age 75, was the founder of The Groundlings, the Los Angeles improvisational theater company whose alumni constitute one of the most extensive rosters of working comedic actors in American entertainment history. Austin founded The Groundlings in January 1974 from informal workshops he had been running in Los Angeles since 1972, trained at San Francisco State University under directors Jules Irving and Herbert Blau, and developed his approach to improv as actor training through years of performing with The Committee in San Francisco. He stepped down as artistic director of The Groundlings in November 1979 due to creative differences but continued teaching through Gary Austin Workshops in Los Angeles, New York, Seattle, and Washington, D.C., until his death.

John Stoops is a Chicago-based improviser, theater executive, and educator who founded The Revival in Hyde Park in 2015 on the site of the corner of 55th Street and University Avenue where the Compass Players had performed in 1955, returning improvisational comedy to its historical birthplace sixty years after it first appeared there. Before founding The Revival, Stoops worked at the Leo Burnett advertising agency in Chicago, performed at iO and Second City, joined Boom Chicago in Amsterdam as a professional ensemble member performing over two hundred shows across five countries alongside Seth Meyers and Jordan Peele, and earned an MBA from Northwestern University's Kellogg School of Management, writing The Revival's founding business plan as his graduation project. The Revival serves South Side Chicago audiences with adult and youth classes, workshops, performances, and scholarship access through its Due South Foundation.

Josephine Forsberg is a Chicago-based improvisation teacher and theater administrator who trained under Viola Spolin, became Spolin's teaching assistant, and took over the central improvisational teaching role in Chicago when Spolin relocated to the West Coast. In the early 1970s she founded The Players Workshop, widely described as Chicago's first fully structured independent improv school, where she organized exercises into a graduated syllabus, built a faculty, and created a pathway through which large numbers of students could study improvisation outside the Second City company structure. She also helped run the Second City Touring Company, produced children's theatre programming, and in the early 1980s invited David Shepherd back to Chicago, helping create the conditions from which ImprovOlympic would emerge.

Keith Johnstone (1933-2023) was the British-Canadian teacher, director, and writer who created one of improv's two major international lineages, distinct from and parallel to the Chicago tradition. Developing his system at London's Royal Court Theatre in the late 1950s and 1960s, then maturing it at the University of Calgary and Loose Moose Theatre Company from 1972 onward, Johnstone built a practice grounded in status dynamics, mask work, narrative play, and competitive formats such as Theatresports. His books Impro (1979) and Impro for Storytellers (1999) became primary texts across dozens of countries, and Theatresports is performed under license in more than thirty nations. For improvisers outside the United States, Johnstone is frequently the foundational figure rather than a secondary one.

Kevin Patrick Robbins is a Canadian, Irish, and British improv teacher, director, writer, and photographer best known as the founder and artistic director of Toronto's Impatient Theatre Co. From 2001 to 2013 he helped build one of Toronto's central long-form training and performance institutions, linking the city's scene to Harold-based lineages associated with Chicago and New York. His later visual practice extends that performance background into commercial, editorial, and artistic portrait photography.

Mick Napier (born 1962) is the founder of The Annoyance Theatre in Chicago, a director, teacher, and author whose work defined one of the field's most influential counter-traditions to conventional improv pedagogy. Where other schools emphasized agreement, politeness, and inherited rules, Napier built a practice around stronger individual choices, stranger material, and a belief that improvisers become better scene partners by becoming more powerful players rather than more deferential ones. His dual presence inside The Annoyance and The Second City made him one of Chicago's most consequential figures in the debate over what improv should look like and how it should be taught.

Co-founder and Workshop Director of Bad Dog Theatre Company in Toronto, which he helped rebrand from Theatresports Toronto in 2003. MacLeod later founded Social Capital Theatre on the Danforth in Toronto.

Founder of Unexpected Productions in Seattle in 1983. Dixon is an innovator in narrative long-form improvisation and has performed and taught internationally. His theatre in Pike Place Market has been a fixture of Seattle's arts scene for over four decades.

Founder of the Ligue Nationale d'Improvisation in Montreal in 1977. Gravel created the hockey-style competitive improv format out of the Theatre Experimental de Montreal, establishing a distinctly Quebecois tradition that spread across the francophone world.

Founder of Hoopla Impro in London in 2006. Roe has been instrumental in growing the UK improv scene, building Hoopla into London's largest improvisation training company. He is the author of The Improv Book, a guide to improvisational techniques.

Founder of The Premise in New York City and a member of the original Compass Players in Chicago. Flicker opened The Premise on Bleecker Street in 1960, creating one of the first improvisation-based theatres in New York. He later directed the film The President's Analyst and co-created the television series Barney Miller.

An improv producer and teacher who founded DSI Comedy Theater in Durham, North Carolina. Ward served as a producer of the Toronto Improv Festival, associate producer of the Chicago Improv Festival, and managing director of ImprovBoston.