The Scottish Conservative leader tweeted a picture of the X-files star in lingerie as she signed off the social network for a fortnight.
The post, which has had nearly 1000 likes, divided opinion among users on the social network as some questioned whether the tweet objectified women or if a similar tweet would have been acceptable by a male politician.
@iain_gannon wrote: “If a male posted this he would be accused of objectifying or demeaning women, just saying.”
@GillianSproule added: “Not questioning Gillian Anderson’s right to be photographed. However, imagine for a moment John Swinney or Alex Salmond had tweeted this.”
While @izetanna raged : “You’re supposed to be a LEADER!! This tweet is tacky and inappropriate, What the hell were you thinking...?”
The tweet comes after Ms Davidson publicly challenged the Democratic Unionist Party to drop its opposition to gay marriage, revealing that she has personally lobbied the party’s leader Arlene Foster over the issue.
In a further apparent dig at Northern Ireland’s largest party, the MSP for Edinburgh Central highlighted her intention to marry her partner Jen Wilson, a Catholic Irishwoman.
One Twitter user suggested Ms Davidson’s tweet may be a tongue-in-cheek attempt to antagonise the DUP further.
@JohnTudor1 tweeted: “Your DUP pals won’t like slightly provocative pictures like that, eh Ruth?”
Yet many more laughed and took the picture as a bit of fun: “Haha brilliant Ruth! Gotta (sic) love a senior politician who doesn’t take themselves too seriously. Keep it up, and have a good break,” @MatthiasSchilf said.
@tuppermeg added: “Ruth. You rock.”
And @alistairmorton tweeted: “Boom!! There’s why I voted for you!!”
Ms Davidson has said she supports a march for gay marriage taking place in Belfast on Saturday.
“Northern Ireland is the only part of the UK where equal marriage is still prohibited. I’ve campaigned passionately for this to change,” she said.
“I’ve raised the issues with Arlene Foster, leader of the DUP, and have sought and received assurances from the prime minister that the Conservative Party will use our influence to press for marriage equality.”
The DUP has scuppered any change in the law despite a majority of MLAs supporting a move towards equal marriage at the most recent vote.