All-inclusive stalwart running weddings and sweet 16s in the same week.
Watermill puts a real price on the internet, which on this island is unusual enough to lead with. Thirteen thousand dollars, one hundred guests, January or February. Then it does the thing almost nobody does and prints the part that normally surfaces on page four of a contract. That means a 22 percent facility fee and New York State tax on top. It adds a flat statement that the fee is not a gratuity and the staff do not receive it.
Watermill's winter page is the most complete first party price statement on this stretch of Smithtown, and it applies to two months. Everything else is a form. The per additional guest line on Here Comes The Guide is lower than the venue's own; the gap is small, but the venue's figure is the one to budget. What the same package costs in a peak month is the number to carry in. Whether the vendor packages The Knot lists at four price points are quoted before or after the 22% is the follow up.
We read the venue's homepage, weddings pages and winter wedding special page, then The Knot, WeddingWire, Here Comes The Guide and a Long Island catering halls directory. Checked September 2026. First party means the venue’s own site or rate card; marketplace means The Knot, WeddingWire, Zola, Wedding Spot or similar. Nothing here is averaged or estimated.
The only first party dollar figures belong to a date limited winter special for January and February 2027; Here Comes The Guide prints a lower per additional guest rate than the venue does.
Their Winter Wedding Special page lists $13,000 for 100 guests, flagged as limited availability for January and February 2027. Additional guests run $130++ per person. What’s inside: the Signature Hampton Menu, cocktail hour, nine dinner entrée selections, dessert, a custom wedding cake and premium open bar, in the renovated ballrooms with private wedding suites.
Read the date slots, because they are the honest part of the offer. Friday evenings, Saturday afternoons, Sunday afternoons and evenings. Saturday evening is “inquire.” That is a winter fill package for the slots that do not sell themselves, priced accordingly, and there is nothing wrong with that as long as you know which slot you are being quoted.
Every price on that page is subject to a 22 percent facility fee and New York State tax. Watermill states outright that the facility fee is retained by the caterer and will not be distributed to employees as a gratuity or tip, and that no gratuities are included in the price of the event. Almost no venue on Long Island writes that sentence down. It is the single most useful line on the site.
Do the arithmetic before you tour. Thirteen thousand plus 22 percent is $15,860, before sales tax, and before a dollar of the tipping that the page has just told you is still on you. Then add the ceremony, the extra thirty guests at $130++ each, and the upgrades. Our cost calculator takes the facility fee and the tax as inputs precisely because of packages shaped like this one, and our pricing page is where the Suffolk comparisons live.
There is also a vendor bundle sitting on their own server as a PDF sales sheet: Wedding Vendor Package W, $9,995 plus tax and the same 22 percent facility fee. It covers photography with a thirty-image digital album, an hour of cocktail music and a four-hour DJ with basic lighting. It includes ten centerpieces plus bouquets and boutonnieres, and up to 100 invitations, with envelope addressing offered at a discount. It also has an eight-hour content creator turning around raw files within 24 hours, and hair and makeup for the bride plus one for up to four hours.
Two caveats, both from the sheet itself. You contact the vendors directly to check availability and secure services, so this is a negotiated rate card rather than a single point of contact. And the file is named for October 2024. Ask whether the roster and the number still stand before you build a budget on it.
We have not been able to locate a capacity number on watermillcaterers.com, indoor and outdoor settings, indoor and outdoor chapels for the ceremony. It does not publish a ceremony fee, individual room names or room capacities. Here Comes The Guide’s listing carries numbers Watermill does not: 425 seated indoors, 200 seated for an outdoor ceremony, 600 standing, a ceremony fee of “$1,000/event and up,” and the same 22 percent administrative fee.
That listing also quotes additional guests at $125++ where Watermill’s own page says $130++. Trust the venue. It is a five-dollar gap that becomes $750 across an extra 150 heads, and it is a good demonstration of why the aggregator number is the one to check last.
Address is 711 Smithtown Bypass, which is Route 347, easy in from the Northern State via Route 111 and genuinely central for a guest list split between Nassau and eastern Suffolk. Ask how many events run in the building on your date. A room this busy is a room that has practiced, but it is also a room that has neighbors.
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