Kill them, teleport them, then revivify them.
The rules suggest that a corpse is not a creature, rather is an object. This is explored in detail in this Q&A: Is a dead creature's body considered an "object"?
Assuming this, if you have access to the spell revivify, you could kill the hostage, then teleport the party by whatever usual means you have that doesn’t allow unwilling creatures, and then cast revivify or whatever resurrection spell suits your fancy upon arrival.
It should be noted however, that the Dungeon Master's Guide has this general rule concering resurrection magic:
A soul can’t be returned to life if it doesn’t wish to be. A soul knows the name, alignment, and patron deity (if any) of the character attempting to revive it and might refuse to return on that basis. For example, if the honorable knight Sturm Brightblade is slain and a high priestess of Takhisis (god of evil dragons) grabs his body, Sturm might not wish to be raised from the dead by her. Any attempts she makes to revive him automatically fail. If the evil cleric wants to revive Sturm to interrogate him, she needs to find some way to trick his soul, such as duping a good cleric into raising him and then capturing him once he is alive again.
So it will be up to the DM if the hostage's soul is willing to return. Maybe if you're nice to them and have promised them freedom later, and they believe you, they'll come back.
You can also use gentle repose to extend the time during which revivify will still work:
You touch a corpse or other remains. For the duration, the target is protected from decay and can't become undead.
The spell also effectively extends the time limit on raising the target from the dead, since days spent under the influence of this spell don't count against the time limit of spells such as raise dead.
So kill your guy, cast gentle repose, and you've got a week and a half to revivify him. Just be careful not to attract too much attention to yourself, people might be suspicious if you're carrying a dead guy.
The 5th level spell teleportation circle let's you drag them through:
Any creature that enters the portal instantly appears within 5 feet of the destination circle or in the nearest unoccupied space if that space is occupied.
Gate is a 9th level spell that creates a portal to a other plane:
You conjure a portal linking an unoccupied space you can see within range to a precise location on a different plane of existence. The portal is a circular opening, which you can make 5 to 20 feet in diameter. You can orient the portal in any direction you choose. The portal lasts for the duration.
Open your gate and carry your hostage through.
Transport via plants
Transport via plants is a 6th level Druid spell:
This spell creates a magical link between a Large or larger inanimate plant within range and another plant, at any distance, on the same plane of existence. You must have seen or touched the destination plant at least once before. For the duration, any creature can step into the target plant and exit from the destination plant by using 5 feet of movement.
For this one, it isn’t abundantly clear how it works with an unwilling creature forced into the plant, so you may need a bit of DM generosity for this one.
Make them willing.
I won't get too much into the details here, but there are a number of ways an unwilling creature can be made into a willing creature, as discussed in this Q&A: Can you make an unwilling creature willing? In other words, what defines “willing”?