The team wants to build a two-story addition to Wrigley Field at the southeast corner of the historic stadium.
The Cubs want to open the sportsbook by the end of 2022 and believe it will take a year to construct.
The plan requires approval from both the landmarks panel and the City Council, which would need to pass an ordinance allowing for sports betting inside major stadiums. Resistance is expected, given fears that a sportsbook would compete with a future Chicago casino.
Last year, a state law legalized sports betting in Illinois.