The ad, which has been aired during ITV shows including ‘Coronation Street’ and ‘The Jeremy Kyle Show’, has drawn the ire of 24 complainants.
Viewers complained to the ASA that the ad was inappropriate because they thought that religious ads were not allowed on TV and that the commercial was potentially harmful because they believed that Scientology was a cult and the ad could exploit vulnerable people.
The 30-second spot features religious imagery of rising suns, pyramids and people having epiphanies, set against more technological shots of dials and circuitry.
"Imagine science and religion connecting," says a voiceover, cueing a burst of blindingly-bright sunlight. "Imagine technology and spirituality combining. Now imagine that everything you ever imagined is possible."
The ad ends with the slogan "Spiritual technology", with the letters rearranging and morphing to spell out "Scientology.org".
The ASA said that it had carefully considered the complaints but decided there were not grounds for further action.
The watchdog said it did understand that some viewers might find the ad in poor taste because they disapproved of the beliefs and practices of Scientologists and because they believed religious ads should not be broadcast on TV.
But the body added: "The Advertising Code does not prohibit ads for religious organisations from being broadcast on channels [such as ITV[.
"The ad itself did not contain either explicit statements of belief or incitements for viewers to change their own beliefs, and only included the advertisers' website address, and so was unlikely to breach the Code for these reasons."
The Code’s rules governing religious advertising are numerous. They include that the advertiser must make clear its identity; that religious ads must not present their religion as the "one" or "one true" faith; and that ads must not appeal particularly to under-18-year-olds or be broadcast during programmes targeting under 18s.