Yes he is, but very distantly. However in Harry Potter And The Deathly Hallows the book when James Potter II says he saw Victoire Weasly (George and Angelina Weasly's daughter) snogging Teddy Lupin Ginny says that she wished they could get married so he would be part of the family. On the other hand in the Order of the Phoenix Sirius says that on the family tree is Bellatrix Lestrange. In Harry Potter and the Deathly Hallows in the meeting at the start of the book discussing between the Death Eaters and Voldermort how Harry will be moved Voldermort jeers at Bellatrix saying that there was a happy event meaning the event of Tonks and Lupin's marriage. Tonks and Lupin are Teddy's late parents so Sirius so is related to Teddy.
In the epilogue of Harry Potter and the deathly hallows Harry marries Ginny Weasly meaning he is related to all the Weaslys. In Harry Potter and the order of the phoenix Sirius says that the Weaslys are related to him but won't be on the family tree because they are blood traitors. Therefore Harry is related to Teddy Lupin.
Edward 'Teddy' Lupin, is the son of Remus Lupin and Nymphadora Tonks. He was raised by his grandmother, Andromeda Tonks with the help of his godfather, Harry Potter.
Teddy Lupin, the son of Remus and Nymphadora (Tonks) Lupin. Teddy was named after Ted Tonks, Nymphadora's father who died shortly before Teddy was born. Harry was chosen by Remus to be Teddy's godfather.
Nymphadora Tonks
It is 2017 and Teddy was born in 1998. Teddy is no longer in school.
Teddy Lupin and Victoire Weasley are kissing on platform 9 3/4
Teddy Lupin
Remus Lupin and Nymphadora Tonks.
Edward 'Teddy' Lupin, is the son of Remus Lupin and Nymphadora Tonks. He was raised by his grandmother, Andromeda Tonks with the help of his godfather, Harry Potter.
Luke Newberry has been cast as Teddy Lupin in Harry Potter and the Deathly Hallows Part 2.
Nymphadora Tonks and Remus Lupin had a son, Edward 'Teddy' Remus Lupin in 1998.
Teddy Lupin, the son of Remus and Nymphadora (Tonks) Lupin. Teddy was named after Ted Tonks, Nymphadora's father who died shortly before Teddy was born. Harry was chosen by Remus to be Teddy's godfather.
Nymphadora Tonks
Lupin visited Shell Cottage to announce that his son Teddy had been born. He also announced that Harry Potter was Teddy's godfather.
Teddy Lupin, whose full name is Ted Remus Lupin, is the son of Remus Lupin and Nymphadora Tonks. Teddy is named after Ted Tonks, Nymphadora's father who was murdered by death eaters, and is Harry Potter's godson. Teddy was born in April 1998, and is a metamorphmagus like his mother.
It is 2017 and Teddy was born in 1998. Teddy is no longer in school.
No Luke Newberry was cast as Teddy but the scene was later cut.
Nymphadora Tonks Remus Lupin and Nymphodora Tonks get married in the Deathly Hollows. They also have a baby boy, Teddy Lupin, Godson of Harry Potter