Did you know that if two people have the same surname and they look similar, that they're highly likely to be related? The concept of how surnames work seems so excruciatingly simple that you'd think it would be impossible to not know that some of the entries on this list are related. However, when you take into account that so many actors decide to change their names for the stage, divorce each other like crazy and don't actually look anything like their relatives, then you start to realise that simply having the same last name doesn't always make a connection easy to make. Some aren't related by blood either, making the pairing just that little bit harder to find. Like always though, it's time to come to the rescue to provide some examples of the lesser-known familial relationships in Hollywood. Tom Cruise's real surname being Mapother and Game Of Thrones actor Oona Chaplin should give you at least a little hint as to who they're related to. When Genealogy starts to get difficult though, is when you start finding out that a giant portion of Hollywood is related through distant relatives. Second cousins, tenth cousins and fifteenth cousins (once removed) are all family ties that make an appearance here. We won't spoil every entry for you though, as your eyes need to at least do some reading. Check out the list below and see which ones you already knew or truly can't believe.