Pools boss Colin Cooper made the decision on Monday and it marks a milestone moment for the 29-year-old midfielder.
Sweeney is set to take part in a record 13th season at Victoria Park and currently sits fourth in the club's all-time appearances list behind Ray Thompson, Watty Moore and Ritchie Humphreys.
"I'm delighted actually, I'm really honoured and it means a lot," he told the club's official website. "It wasn't something that I expected if I'm being honest but the gaffer sat me down and had a chat about it in Holland.
"Maybe I should have been a lot more positive about it but he caught me totally by surprise at the time but now I've had time to think about it I'm really pleased.
"When the gaffer talked to me he just basically wanted to make sure I was okay with it; he didn't want it to affect performances because I think sometimes it can weigh heavy on you."
He added: "What's nice is that I have had a lot of the former captains on the phone or texting me congratulations. Ritchie Humphreys, Michael Nelson, Sam Collins and Peter Hartley have all been on.
"I'm not sure it will change a lot around the dressing room - we have captains in there in Sam and Peter and they won't lose their voices and they will still be vocal and drive the team on as they always have."