The 26-year-old back-rower takes over the reins from Jonathan Davies.
Pembrokeshire product Macleod led the side impressively in the second half of last season in Davies’s absence through injury, guiding the Scarlets to the semi-finals of the European Challenge Cup.
He made his Scarlets debut in 2015 and has played 112 matches for the club, making his mark during the Pro12-winning campaign in 2016-17.
Macleod’s outstanding performances in the Scarlets jersey saw him win his first Wales cap last November and he was named in Wales’ initial Rugby World Cup training squad before being released because of a shoulder injury.
Macleod is close to making his return from that injury as Scarlets begin their United Rugby Championship campaign in South Africa against the Vodacom Bulls this coming weekend.
“It is a huge honour for me as someone brought up in the region to captain a club with such a proud history and to follow in the footsteps of some great Scarlets like Foxy and Ken, who I have learned a huge amount from during my time here,” he said
“I enjoyed the captaincy last season, particularly during our run in the Challenge Cup which highlighted how much young talent there is within this squad. There were also some standout performances at home in the URC.
“It’s been a long, tough pre-season; the boys have worked hard as always and we’re looking forward to kicking off our campaign in South Africa against the Bulls and Stormers over the next fortnight. For us, the challenge is to build on the foundations we laid last season, both in the URC and Europe.
“From a personal point of view, It has been frustrating missing a chunk of the summer recovering from shoulder surgery, but I’m not far away and I can’t wait to get out there with the boys again.”
Scarlets head coach Dwayne Peel said: “Josh is an exceptional player who leads by example, someone who commands respect and has been a big part of this squad for a number of years.
“He displayed his leadership qualities last season and we were all impressed by how he carried out the role, on and off the field.
“Jon will continue to be a big part of our leadership team here, his experience in the game is invaluable and will be a huge help to Josh, as will our other senior players in the squad.”
