Hello how may I help you? I want to know a world record. I'd be happy to look up a world record for you! I want to know who is the tallest person in the whole world. Are you looking for the tallest living person or the tallest person of all time? All time. The tallest person of all time is Robert Wadlow. How tall was he? Robert Wadlow was 8 feet 11 inches tall. Wow, that's really tall. Thanks for the information. No problem!