(At about seven minutes into the film) When Tim watches Boss Baby exit the car, Tim is wearing a shirt with the digits "01" imprinted. However, when he gets down the stairs, the digits change to "02." This indicates his being relegated to second place by Boss Baby.
Young Timothy (Miles Bakshi) has a Gandalf-themed alarm clock. Bakshi's grandfather, Ralph Bakshi, directed the original The Lord of the Rings (1978).
Alec Baldwin's line, "Cookies are for closers," is a spoof of his Glengarry Glen Ross (1992) line, "Coffee is for closers."
When Tim jumps up to his home's second story during the early chase scene, the sound effect is from The Six Million Dollar Man (1974).
The first trailer was released on National Boss' Day.