Can my landlord just refuse to let me sell my business because they don't like the buyer?

Not usually, but it depends entirely on what your lease says. Most commercial leases prohibit assigning the lease to a new tenant without the landlord's consent, and many go further and state that consent cannot be unreasonably withheld. Under the Commercial Tenancies Act, where a lease restricts assignment without consent, an implied proviso that consent not be unreasonably withheld is read in unless the lease expressly says otherwise — but there is no general reasonableness standard supplied outside the lease's own wording the way there is for residential tenancies.

Personal dislike of a buyer, on its own, is a weak reason. Landlords are generally expected to point to legitimate concerns — the buyer's financial strength, business experience, or intended use of the premises. But if your particular lease gives the landlord broad, unqualified discretion to approve or refuse an assignee, that discretion can be harder to challenge.

Before you get far into a sale, read your lease's assignment clause carefully and, if the landlord raises a vague objection, ask for the actual reason in writing. A Treadstone business lawyer can review the clause and push back where a refusal looks unreasonable.