Franny's Mother, played by Joanna Gleason, sings very badly in the movie and is asked numerous times by her daughter not to sing. In fact, Gleason has a very good singing voice and has appeared in several Broadway musicals, including "Into the Woods" for which she won the 1988 Tony Award for Best Actress in a Musical.
Jennifer Love Hewitt was developing a separate film with the same premise for her to star in but was forced to cancel the project when this film was released.
Brendan Fraser was set to play the role of Dr. Steve/Eddie, but scheduling conflicts with filming the movie Bedazzled (2000) prevented him.
Sarah Michelle Gellar was originally set to star, but had to drop out because of scheduling conflicts from Buffy the Vampire Slayer (1997).
In an early scene in Matthew McConaughey's office, he indicates a framed picture of his "sister". The prop is actually a picture of associate producer and choreographer Anne Fletcher, who had a scene in the movie that was cut.
The first old Movie played in the park is 'Two Tickets to Broadway' (1951) starring Janet Leigh and Tony Martin.
Mary's boss, Geri, is married to the best man that Mary fed the toast to in real life.
Bree Turner, who plays the bride needing comforting by Jennifer Lopez at the beginning of the movie, also opened another wedding movie, as a bridesmaid in the opening title sequence performance in "My Best Friend's Wedding".
At the first wedding, Jennifer Lopez's character Maria comforts the bride by complimenting her great thighs. This may be a small reference to the huge media focus on Jen's "big" thighs when she first began her singing career.
The taxi driver in the beginning of the movie, that hits the dumpster that Steve saves Mary from, is the same taxi driver that drives Steve to city hall towards the end of the movie.
May hold the unofficial Hollywood record for most credited producers of any movie ever made: fourteen, including six "executive producers", six "producers" and two "co-producers".