NBC's "The New Normal" and "Smash" and "Go On" and CBS's "Partners," will get the ax, the Hollywood Reporter said Saturday.
Heather Morris, who plays a bisexual on Fox's "Glee," will not be returning next season, the Reporter said.
A Hollywood Reporter survey in November discovered that gay characters on TV, including couples on "Grey's Anatomy" and "Modern Family," helped voters to support gay marriage at the polls.
"This data would suggest that seeing this stuff makes it more socially acceptable. Views on gay marriage have exponentially gone in its favor since 2002," THR pollster Jon Penns said at the time.
The THR poll came a month after watchdog group Gay & Lesbian Alliance Against Defamation released its annual "Where We are on TV" report that found a record number regular LGBT characters on the small screen.
"The sheer number of characters who will no longer be on the air means diversity on television is once again at risk. Following a season with the highest recorded number of lesbian, gay, bisexual and transgender characters, these cancellations mean networks have to make a concerted effort to ensure the 2013-2014 season truly reflects the diversity of their audience," Gay & Lesbian Alliance Against Defamation national spokesman Wilson Cruz said.