You can wear loafers to a wedding.
Loafers are a versatile option that you can dress up or down depending on the rest of your outfit.
Opt for loafers in leather or suede with a polished finish.
I've worn loafers to weddings and find them very comfortable as well.
Loafers are great to wear in most places except in an office as loafers do not really transcend business casual attire.
That is, given their roots in casual wear, there's a stigma attached to wearing them that makes formal business attire environments off limits for this particular shoe.