John having sweaty palms when he shakes Sheila's hand is possibly a call back to the first film when John had sweaty palms when he met Nora Jones.
On the wall of John and Ted's bedroom is a onesheet for Darkman (1990). That film starred Liam Neeson, who had also appeared in Ted 2 (2015).
Scott Grimes, Penny Johnson Jerald, and Seth MacFarlane (Matty Bennett, The Principal, and the voice of Ted, respectively) worked together as main cast members on McFarlane's Star Trek parody series The Orville (2017), as Lt. Gordon Malloy, Dr. Claire Finn, and Capt. Ed Mercer, respectively. Giorgia Whigham also had two guest appearances in it in Majority Rule (2017) and Future Unknown (2022).