Do you have to make a reservation?

No but you should if you want to make sure you have a table.

No

Hello Racheal, Delmonico's is excellent dinning. We did not make a reservation on a busy day. We were seated within 10 minutes. Reservations are not required. My hotel was across the street. We walked and enjoyed a great dinner.

Not if you want to sit at the bar. They have great appetizers specials and there's always a good drink... But, if you want to sit down and have a table, you might want to call ahead.