The present disclosure relates to anti-CD40 antibodies, such as humanized anti-CD40 antibodies, that may be used in various therapeutic, prophylactic and diagnostic methods. The antibodies generally block the ability of CD40 to bind CD154 and do so without activating the cell expressing CD40 (e.g., a B cell). The present antibodies or fragments thereof may be used to reduce complications associated with organ or tissue transplantation.