The two were initially just friends at St. Andrews, but an on-again, off-again romance bloomed on campus, developing into the full blown love affair that has captivated a nation.
The couple helped celebrate the 600th anniversary of the University of St. Andrews, where they met as students. It was only their third public appearance since announcing their engagement in November.
Prince William called the visit a "special moment" for the couple as he addressed a reception in the university quadrangle. Middleton looked on from her seat on the stage. Middleton, who wore a red suit with black accents, smiled and pushed windswept hair off her face as she gazed at her fiance.
Thousands lined the cobblestoned streets in hope of catching a glimpse of the royal couple. Well-wishers of all ages and nationalities stood six deep in some spots, stretching out flowers and hands.
Middleton is set to marry the prince on April 29 at Westminster Abbey.
In what is believed to be the couple's first official wedding gift, Richardson said the university is bestowing a scholarship for underprivileged students worth 70,000 pounds ($113,000).
The Associated Press contributed to this report.