Is it Bill's graduation or Bills' graduation?

Answer:

Bills' graduation

But only if: It is the Buffalo Bills football team graduating to another level in the playoffs. Perhaps you are wanting to write that: "Bill's graduation to the third grade earned him a summertime party at Chuck E. Cheese's!".
First answer by ID1453280605. Last edit by LeastDuck. Contributor trust: 691 [recommend contributor recommended]. Question popularity: 5 [recommend question].