iO Theater (ImprovOlympic)
1981-present (iO West closed 2018; iO Chicago closed 2020 and reopened 2022 at a new location) · Chicago / Los Angeles (West)
Also known as iO, ImprovOlympic, Improv Olympic, IO
The Chicago long-form institution Del Close and Charna Halpern co-founded in 1981 around a single idea: that improvised scenes could add up to a full evening of theater. Home of the Harold. Where Tina Fey, Amy Poehler, Stephen Colbert, Mike Myers, Chris Farley, and most of American comedy trained.
Known for
- Founded 1981 by Del Close and Charna Halpern as ImprovOlympic, renamed iO in 2005 after IOC legal pressure.
- Home of the Harold — the 30-minute long-form structure Close developed there through the 1980s that became the foundation of modern long-form improv worldwide.
- Trained Tina Fey, Amy Poehler, Stephen Colbert, Mike Myers, Chris Farley, Rachel Dratch, the UCB four, TJ Jagodowski, Dave Pasquesi — most of the last three decades of American comedy passed through iO Chicago at some point.
- iO West (Los Angeles) opened in 1997 and closed in 2018 after two decades of serving as the LA feeder for the franchise.
- iO Chicago closed in June 2020 amid the pandemic and accountability concerns; reopened in November 2022 at a new Clark Street location under Charna Halpern's continued leadership.
Connected to
Notes
iO is the umbrella for the Chicago and West (LA) locations, plus the brand, plus the founders’ legacy. Individual locations have their own entries: schools/io-chicago and schools/io-west.
The difference between iO and schools/second-city-chicago matters: Second City is sketch-first, with improvised material workshopped into scripted revues; iO is long-form improvisational theater, with the Harold as its signature form. Most Chicago-era improvisers trained at both.
iO’s closure in 2020 (before reopening in 2022) reshaped the Chicago long-form scene — it was during that gap that many of its most notable teachers and performers dispersed to other theaters, podcasts, and LA.