The 37-year-old "Saving Mr. Banks" star made the comments on "The Ellen DeGeneres Show" Monday.
Farrell said he had his publicist contact Taylor's representatives and set up a meeting in 2009.
"I got to have an audience with her," he told DeGeneres. "And that was the beginning of a year and a half or two years of what was a really cool [relationship]. It was kind of like the last -- it feels like in my head, not hers, I'm projecting -- but the last kind of romantic relationship I had. Which was never consummated."
Farrell went on to say he and Taylor both had trouble sleeping so he would call her up and talk to her into "the wee hours."
"I just adored her," Farrell said. "She was a spectacular, spectacular woman. I wanted to be [husband] No. 8, but we ran out of road."
Taylor died at the age of 79 after years of poor health.