Ben McKenzie stated that for inspiration for his character, he basically became the younger version of Gary Oldman's portrayal of Jim Gordon from the Dark Knight Trilogy.
In the Wayne study on a shelf sits a bust of William Shakespeare, the same kind used to activate the secret passageway to the bat cave in the 1960s Batman and Robin series.
Showrunner Bruno Heller stated that Gotham is not set in any time period. To achieve this effect, older and outdated technology such as rotary phones, CRT monitors, tube televisions are seen used throughout the show as well as contemporary devices like cell phones.
Robin Lord Taylor is a fan of Danny DeVito's portrayal of the Penguin in Batman: O Retorno (1992). Carol Kane, who plays Penguin's mother, co-starred with Danny Devito in the TV series Taxi (1978). They remained friends after the show ended. Robin Lord Taylor stated that Carol Kane came back to the set after having lunch with Danny Devito and relayed the message that "[De Vito] watches the show and likes [Taylor's] performance." This comment sent Robin Lord Taylor "over the moon."