Orlando Bloom admits to Cate Blanchett that he had a crush on her during 'Lord of the Rings' filming

Before Katy Perry, Orlando Bloom had his eye on another big star.

On Monday's episode of The Late Late Show with James Corden, which was taped in London, the 41-year-old actor joined Cate Blanchett on the guest couch and confessed that he had a huge crush on her while the two were filming The Lord of the Rings.

When asked what his first impression of Blanchett was when she was playing Galadriel and he was portraying Legolas in LOTR, Bloom admitted, "I can’t think -- I had such a crush. I had the biggest crush on you."

Taken aback by the confession, Blanchett tried to give Bloom an out, saying, "Well, it was your character!"

Bloom stuck to his story, exclaiming, "No, it was me!"

Bloom noted that he was about 21 years old at the time of the filming and was intimidated by Blanchett, more than five years his senior. "What was I, 110?" the 49-year-old actress quipped.

The crush wasn’t mutual, but that may just be because Blanchett didn’t know who Bloom was for a large portion of her three weeks on set.

"I didn’t recognize you, because the first time I saw you, you had hair -- like Fabio hair and blue eyes," Blanchett recalled. "And then I just saw you -- who is this really cute guy out of drama school -- and I didn’t put two and two [together]."

Bloom chimed in, "And I was just walking around spying on her from the corner of the room -- in a non creepy way."

While Blanchett may not have been swooning over Bloom, someone else was -- Corden’s mother, Margaret. With TheLate Late Show filming all week in London, the host's family was in attendance to show their support. While Corden’s dad, Malcolm, was adorably filming the televised program from his seat, his mom was hanging with Bloom.

"She’s backstage with Orlando Bloom. Well he’s on her list," Malcolm said of his wife. "Mom and I have been married so long we both have these lists of celebrities we’d be allowed to keep company with, should our paths ever cross. I believe in America they call it a hall pass."

While Bloom was feeding Margaret fruit while lounging in a robe, Malcolm revealed his real reason for being so cool with the arrangement. "I’m fine with it because Cher’s going to be here tomorrow," he joked. "She’s on my list."

Another girl going gaga for Bloom is Perry, his on-again, off-again girlfriend.

"They know each other’s patterns and the communication between them has improved, so their relationship is thriving," a source exclusively told ET last month. "They are happier than they've ever been and feel in time they will be ready to be more public about their love for one another and can plan for a future."

The source continued: "They are talking about a future wedding, but they are taking it slow."