Lee carded a four-under-par 67 at Pine Needles Lodge and Golf Club to be tied for third after the opening round.

The in-form World No.4 rolled in seven birdies and briefly held the lead outright at five-under before finishing the day three shots behind American Mina Harigae.

Swede Ingrid Lindblad fired the lowest round by an amateur in the 77-year history of the U.S. Women's Open, a six-under 65, to hold the clubhouse lead for much of the day.

"She was fearless," said playing partner Annika Sorenstam, Sweden's most famous female golfer.

Fellow Swede and three-time major champion Anna Nordqvist shares third with Lee along with American Ryan O'Toole, one stroke ahead of U.S. duo Lexi Thompson and Ally Ewing.

Mina Harigae leads after round one of the U.S. Women's Open. PHOTO: USGA.

As well as eyeing a second career major following her breakthrough at last year's Evian Championship in France, Lee is chasing the biggest cheque in women's golfing history.

The victor on Sunday will pocket a cheque for $US1.8 million ($A2.5 million) out of the record $US10 million ($A13.7 million) overall purse, and Lee fancies her chances after a solid start.

"Today I actually putted really well, and usually I hit it better than my putting," she said.

"But I've been working really hard on all aspects of my game, so I feel like I'm pretty confident just in my ability right now."

The 26-year-old tuned up for the season's fourth women's major with victory at last month's Cognizant Founders Cup, her first LPGA Tour win of the year.

Lee's Tokyo Olympics teammate Hannah Green is the next-best Australian after opening with a one-under 70.

Grace Kim posted a 73 in her first major as a professional and Sarah Kemp had a 76.

Still in college and with no immediate plans to turn pro, Lindblad isn't eligible for the monster winner's cheque.

But the 22-year-old still believes she can win.

"Yeah, it's possible," she said.

Three amateurs had previously shot 66 – Carol Semple Thompson in 1994, Brittany Lincicome in 2004 and Gina Kim in 2019.

Catherine Lacoste, the daughter of French tennis player Rene Lacoste and 1927 British Ladies Amateur champion Simone Thion de la Chaume, was the only amateur to win the U.S. Women's Open back in 1967.