Methods and apparatus to collect impressions associated with over-the-top media devices are disclosed. Example disclosed apparatus include a device identifier collector at a first server, the device identifier collector to: receive a first request initiated at a user-controlled client device, the first request including a client device identifier that identifies the user-controlled client device and an over-the-top device identifier that identifies an over-the-top device that presents media via a media presentation device, the over-the-top device different than the user-controlled client device; forward a mapping identifier and the client device identifier to a second server of a database proprietor, the mapping identifier associated with the over-the-top device identifier. Example apparatus also include an impressions collector at the first server, the impressions collector to: receive a second request initiated by the over-the-top device, the second request including the over-the-top device identifier and a media identifier; and forward the mapping identifier and the media identifier to the second server of the database proprietor. Example apparatus also include a demographic collector to receive aggregate demographic impressions from the database proprietor, the aggregate demographic impressions including the media identifier and demographics corresponding to the user of the user-controlled client device.