Significant portions of the movie interactions between major characters were ad-libbed. The actors playing the leading roles all knew each other well and improvised dialogue as well as or better than the script.
The "Ocean's Eleven" group appear on camera together in only a single shot. It is at the very end of the movie as they are walking on the sidewalk in front of the Sands.
The casinos hit in the heist are: Hotel Flamingo, the Sands, Desert Inn, the Riviera and the Sahara.
The entire Ocean's Eleven does not all appear at the end as previously stated, since they were leaving Tony Bergdorf's (Richard Conte) funeral who was one of the eleven. There are however at least two scenes with all of the group together, at Spyros Acebos (Akim Tamiroff) house and at the Bowling Alley.
The lead characters all served together in the 82nd Airborne division during WWII.
The ritzy Beverly Hills home of Spyros Acebos (Akim Tamiroff) actually belonged to Hollywood agent Kurt Frings, husband of then screenwriter Ketti Frings.
Writer Jack Golden Russell was a gas station attendant in Vegas who handed the script to Sinatra while he was refilling his car.