Actress Cleo King portrays the character of Grandma to Reno Wilson's character, Officer Carl McMillan. However, Wilson, born January 1970, is only 7 years 5 months younger than King, born August 1962; possibly the smallest age difference between actors playing grandchild and grandparent in regular series television history.
It has been established in several episodes that Mike's personal car is an older (very) model Mitsubishi Galant with bad brakes.
The name of the school where Molly teaches is Walter Payton Elementary School in the Chicago Public School System, a fictional school (although the Chicago School District did name a high school, Walter Payton College Prep, in Payton's honor). Walter Payton, an NFL Running Back with the Chicago Bears for 13 seasons, was a Chicago legend who died in 1999 at age 45 from a rare autoimmune liver illness, leaving behind a charitable philanthropic trust which distributes toys to underprivileged children and maintains a cancer and liver research fund.
While discussing potential baby names, Carl announced that his middle name is Enoch (s3/ep4), in case Molly wants to choose that for the baby's name.
When Molly walks in on Mike reading in bed, he's reading 'The Sisterhood of the Traveling Pants'. Melissa McCarthy, who plays Molly, played Sookie St. James on Gilmore Girls with Alexis Bledel, who played in 'The Sisterhood of the Traveling Pants'.