If you want to have a Wishes Wedding than no, you must have a full reception which meets certain total expenditures as well as minimums in Food and Beverage. If you're interested in only have a ceremony you can look into either the Memories or Escape Collections.
The Memories collection is about an hour in length total and is for your (and your fiance) as well as up to 4 other Guests (so a total of 6). You must book a hotel stay to have this package but inside the package you will get either a limo or in-room celebration, a photographer, floral for the bride and a violinist. You may add on additional small items (floral, park photo package, etc.) for a fee. This only includes a ceremony and does not include any type of reception.
The Escape Collection is for you and your fiance and up to 18 total Guests. It includes the ceremony and then a small cake and champagne celebration. There are stock packages to choose from so it isn't as customizable as a Wishes Wedding but you get more than with the Memories package.
You can also look at booking a dessert party or something similar through Disney Catered Events but keep in mind if you do choose to go this route, you won't be allowed to wear any of your wedding attire (re: Bridal Gown) into the park. That is a privilege reserved for those Brides that have booked an in-park event through Disney's Fairytale Weddings and Honeymoons.
Hope that helps! Let me know if you have any other questions! =)