Karol Martesko-Fenster (born March 12, 1961) is an Austrian-born American entrepreneur and cross media executive. He has been active in the motion picture, publishing, music television and Internet industries for over two decades including leadership in the American independent film industry.
Most recently Martesko-Fenster was the General Manager of the Film Division at Chris Blackwell's Palm Pictures Entertainment Properties and President of Palm’s RES Media Group. During his five-year tenure he supervised the strategic re-organization of the film division and oversaw the company’s successful theatrical releases of Scratch and Sex and Lucia. While at Palm, he led all operations and brand positioning for the RES Media Group business unit, including its digital film festival RESFest, the world’s original digital arts and entertainment festival, which in its final year (2006) was a global touring event spanning six continents, 19 countries and over 40 cities worldwide.
Prior to joining Palm, Martesko-Fenster was the President of Rising Tide Studios, an integrated media and convergence company founded by Jason Calacanis. As President & Publisher Martesko-Fenster supervised the growth and development of the Silicon Alley Reporter  and Digital Coast Reporter magazines and numerous high profile conferences on the Media, Finance and Technology Industries.
In the early 1990s Martesko-Fenster co-founded and launched Filmmaker (magazine), indieWIRE, RES (magazine), and The Virtual FilmFestival. In the late 1980s Martesko-Fenster was a coordinating producer for Great Performances Music on PBS and produced music television programs and live satellite broadcasts. Martesko-Fenster was the Market Director for the breakout 1989 Independent Feature Film Market, the inaugural event at the Angelika Film Center. In 1990, as the Acting Executive Director of the Independent Feature Project, Martesko-Fenster restructured the film membership & service organization and initiated the inaugural Gotham Awards.
Karol joined Babel Networks in September 2008 after providing strategic consulting services to numerous film and media ventures, including Arts Alliance, FILMHAUS Vienna, T5M, Tribeca Enterprises, CINELAN and The WorkBook Project. As the Senior Vice-President/General Manager of Babel Networks US, Martesko-Fenster leads the film division for Babelgum, the global web, mobile and IPTV destination.
Martesko-Fenster produced documentary and feature films including Frank Dead Souls, Scenes From The New World, Myth or Reality: The von Trapp Family and Vienna 1900. He is credited as an Executive Producer on Floored (Documentary Film), Dark Fibre and Wetlands Preserved and collaborated with Richard Linklater on Before Sunrise.