The dance sequence during the wedding was choreographed by the same person who worked on "Cafe Disco", with all of the dancing pairs having 45-minute practice sessions to get their moves down.
Erin actually flashes the camera when dancing down the aisle.
When Jim and Pam are on the boat going down stream from Niagara Falls, Pam leans her head onto Jim. This is reference to the season 1 episode Diversity Day (2005), where Pam does the same thing before they get together.
This is the second time Steve Carell has acted in something involving the "Maid of the Mist", the first being Bruce Almighty (2003).
When asked how many horses he has, Dwight (a known Harry Potter fan) responds "9 3/4". The platform in Harry Potter where the Hogwarts Express picks up students is platform 9 3/4.