Lascelles is one of the youngest players in the Premier League to hold the armband for his team.
He is only 24 and in his third season as the club captain. Manager Rafa Benitez has entrusted him with a lot of responsibility.
"It's a massive achievement," Lascelles told FourFourTwo magazine.
"I thought it would be a big task in terms of pressure and the expectation of the role, because Newcastle's fans demand the best. But the backing of Rafa Benitez and advice from all of the coaching staff has helped me to adapt quickly.
"I've always liked being the leader of a team and enjoyed the responsibility.
"Whenever I played in primary school or secondary school, I was always captain. When I was at Nottingham Forest I was captain at under-16, under-18 and reserve team level.
"I think the only time I haven't been captain is at youth team level for England and when I first arrived at Newcastle in 2014."