• Episode 1-19 of "Sports Night" is called "Eli's Coming"; episode #41 (2-19) of the West Wing is called "Bad Moon Rising". Both episode titles are songs, one by Three Dog Night, one by Creedence Clearwater Revival.
• Episodes 1-23 of "Sports Night" and #22 (1-22) of the West Wing are both called "What Kind of Day Has It Been"; both are the season 1 finales of their respective shows.
• "Sports Night" episode 1-7, "Dear Louise", features a first-person narrative format where Jeremy is writing a letter; the content of the letter is the narration of the show. West Wing episode #39 (2-17) "The Stackhouse Filibuster", features the staff of the West Wing doing the same thing in the same format.
• Sports Night uses the first-person narrative format again in episode 1-17, "How Are Things in Glocca Morra?", the structure of which bears a striking resemblance to the aforementioned WW episode #39. In both episodes, the premise of the show is that something which should have ended long ago still hasn't: in SN's case, a tennis match between Pete Sampras and unknown Alberto Fedregotti, and in the WW's case, a vote on a bill being delayed by Stackhouse's filibuster. The letters in the first-person narrative format are being written by the shows' characters while waiting for the event to finish. In both shows, the letter writers mention how the event should have ended quickly: "Problem is, nobody told Stackhouse/Fedregotti". (overlap pointed out by Sarah Spooner and Richard)
• Episode 1-1 of Sports Night and Episode #1 of the West Wing feature as part of the plot a main character in danger of being fired. In "Sports Night", it's Casey, whose lackadaisical on-air performance has network execs gunning for his head. In "The West Wing", it's Josh, whose inflammatory comments on a TV show have the Christian right after him. (overlap pointed out by Marybeth I.)
• Dan in episode 1-2, of "Sports Night" "The Apology", gets in trouble when an interview with him in Esquire magazine contains a portion about his support for the legalization of marijuana. The network brass goes crazy, and he is forced to make an on-air apology to his viewers. In episode #37 of the West Wing, "Ellie", the Surgeon General makes arguments for legalizing marijuana during an Internet chat, which causes all hell to break loose in the White House. (overlap pointed out by Marybeth I.)
• Episodes 2-22 of Sports Night and #2 of the West Wing (numerology with the number 2, anyone?) both have Latin titles. The Sports Night show is called "Quo Vadimus", which means "where are we going?"; the West Wing show is called "Post Hoc, Ergo Propter Hoc", which means "after it, therefore because of it". (overlap pointed out by Adam Stinelli)
• Anything for a song! Sports Night and the West Wing both feature an episode where the other characters anxiously await a female main character's rendition of a song. In Sports Night it's episode 1-7, "Dear Louise", where it is revealed that whenever Dana gets a couple of drinks in her she starts singing "Boogie Shoes" by K.C. and the Sunshine Band. In the West Wing it's episode #18, "Six Meetings Before Lunch", where everyone flocks around to see CJ's famous version of "The Jackal" by Ronnie Jordan. (overlap pointed out by Karen Streed)

• Introduction to overlap guide
• "Sports Night" Episode Guide
• Overlaps in actors between the two series
• Miscellaneous overlaps between the two series - underwear turning up in odd places, on national TV without pants, similar romantic encounters, etc.