The exec is currently on maternity leave, but will not return following this after informing the network of her decision to exit.
This comes after CBS Entertainment president Glenn Geller announced he was stepping down after suffering a heart attack, with Thom Sherman and Kelly Kahl brought in to replace him.
Davis joined CBS in 1997 as an assistant and rose to its main drama development executive by 2009. During that time, she developed elements of the CSI and NCIS franchises, plus Scorpion, Criminal Minds, Elementary, Blue Bloods, The Good Wife and Bull among others.
“My two decades at CBS have been the most rewarding of my life, and I can’t thank [company chairman and CEO] Leslie Moonves enough for his leadership and vision,” said Davis in a statement.
“From my first day as a temporary assistant under Nina Tassler, CBS has given me the tremendous opportunity to work with the most talented and dedicated executives, writers, producers and directors in the entertainment industry.”
Moonves called her “a terrific CBS homegrown success story”.
There had been little in the way of executive turnover at CBS for a number of years, though this year has been different. Also exiting in recent months were head of alternative Chris Castallo and head of current Bridget Wiley. Sharon Vuong and Amy Reisenbach replaced them, respectively.