Submissions Only is a comedy web series about the casting and audition process for Broadway theater. It centers around aspiring actress Penny Reilly (Kate Wetherhead) and her friend, casting agency director Tim Trull (Colin Hanlon), and their circle of friends, colleagues, relationships and family.^[1] The series was created in August 2010 by Broadway performers Wetherhead and Andrew Keenan-Bolger.^[2] Wetherhead is the series' writer, while Keenan-Bolger is the main director and editor.^[1]

The series has had three seasons. The first season started airing in October 2010 and had six episodes, the second season started airing in September 2011 and had eight episodes,^[1] and the third season started airing in March 2014 and had eight episodes. Most episodes run between 15 and 20 minutes long.^[1] The first season was produced on a minuscule^{[clarification needed]} budget, and was shown on YouTube. The second and third seasons had significantly larger budget, and higher production quality. Episodes from the second and third seasons were originally shown exclusively on the website BroadwayWorld.com, which also partially funded the project, but were both eventually released on YouTube. Most of the funding for the second and third seasons was solicited through the website Kickstarter.^[1] Broadway producer Kevin McCollum was a producing partner for the third season.^[3]

The impetus for the series was a series of backstage videos that Keenan-Bolger recorded for Music Theatre International, titled Keenan Blogger. Several of the videos were recorded while Keenan-Bolger was in the cast of a production of It's a Bird...It's a Plane...It's Superman in Dallas in 2010,^[4] and Wetherhead, who was also a cast member, assisted in their production. Wetherhead's husband, who was the show's lighting designer, suggested they create a web series together.^[5]

All of the audition material shown is from fake plays and musicals, with dialogue and lyrics written by Wetherhead. For musical numbers, the music was written by Adam Gwon, Adam Wachter, Keith Varney and others.^[5]

Most of the actors who have appeared on the series are Broadway performers who are friends and acquaintances of the creators.

Submissions Only has included cameos by Broadway veterans such as Chita Rivera, Kristin Chenoweth, Audra McDonald, Hunter Foster, Adam Pascal, Jeremy Jordan, Danny Burstein and Brian D'Arcy James, Kelli O'Hara, Heidi Blickenstaff, Lin-Manuel Miranda, actors such as Rachel Dratch, Kristen Johnston, Michael Urie, Bobby Cannavale and Judith Light, and New York Post theater critic Michael Riedel.^[2] The last episode of season two notably had a large number of cameos, including appearances by Jesse Tyler Ferguson, Nick Jonas, Harvey Fierstein, Jack Falahee, and many ensemble members from the Broadway cast of Newsies.