A hinge assembly (10, 110) comprising first (12, 112), second (14, 114), third (16, 116) and fourth (18, 118) links and a locking mechanism (20, 120); the first link (12, 112) being pivotally connected to the second link (14, 114) and being integrally formed with, or adapted to be attached to, one of a vehicle body and a vehicle bonnet; the third link (16, 116) being pivotally connected between the second and fourth links; the fourth link (18, 118) being integrally formed with, or adapted to be attached to, the other of a vehicle body and a vehicle bonnet; and the locking mechanism (20, 120) being engageable with, and releasable from, a lockable link (14, 114; 18, 118), the lockable link being one of the second and fourth links, so as to prevent and allow, respectively, relative movement between the second and fourth links; the third link (16, 116) being engageable with the locking mechanism (20, 120) such that when the locking mechanism is engaged with the lockable link, rotation of the third link from the first to the second position releases the locking mechanism from the lockable link; characterized in that the third link (16, 116) is pivotally connected to the lockable link by a movable pivot (29,129), which allows the third link to be rotated relative to the second and fourth links from a first position to a second position in which the pivot of the third link engages the lockable link; the third link (16, 116) is pivotally connected between the second and fourth links with a first portion of the third link pivotally connected to the lockable link by the movable pivot (29, 129), and a second portion of the third link pivotally connected to the other of the second and fourth links by an intermediate link (34, 134), a first portion of the intermediate link (34, 134) being pivotally connected to the third link by a single pivot (38, 138), and a second portion of the intermediate link (34, 134) being pivotally connected to the other of the second and fourth links by a single pivot (42, 142); the locking mechanism comprises first and second locking members engageable with, and releasable from, respective first (32, 132) and second (58, 158) portions of the lockable link, the first locking member being engageable with the third link (16, 116) and the second locking member, the first and second locking members (212, 204) being arranged such that when the locking members are engaged with the lockable link (14, 114, 18, 118), rotation of the third link (16, 116) from the first to the second position moves the first locking member from a first position, through an intermediate position, to a second position to release the first locking member from the first portion of the lockable link, and movement of the first locking member from the intermediate position to the second position causes the first locking member to engage the second locking member and to release the second locking member from the second portion of the lockable link; and the hinge assembly further comprises an actuator (22, 122) operable to urge the third link from the first position to the second position, in which the moveable pivot of the third link engages the lockable link, so as to release the locking mechanism from the lockable link and to move the lockable link relative to the other of the second and fourth links.