Both players have penned one-year contracts with the Shrimps as they gear up for life in League One.
Mensah (20) makes the journey to the Mazuma Stadium, having previously represented Crystal Palace’s U23s and made 26 appearances for Weymouth last season.
“I’m absolutely buzzing,” he told the club website.
“It’s been a tough 18 months and it’s just nice to be able to get settled at a club.
“We’re getting together as a team, there’s a good feel about the group and there’s nothing but hard work within this group and great talent as well so it’s going to be busy but it’s going to be exciting.”
Manager Stephen Robinson added: “He is a young man at only 20 years of age who we feel will continue to improve and develop the very good attributes he has shown to date in his career.
“Impressively he has already played over 100 games in men’s football but he is still very young and we firmly believe this is the perfect platform to continue his development.”
As for McLoughlin, the 24-year-old former Republic of Ireland U18 international joins Morecambe after two-and-a-half years with AFC Wimbledon.
He began his career at Ipswich Town, progressing through the youth system before joining the Dons in 2019.
“I’m looking forward to getting started,” McLoughlin told the club website.
“We’re a couple of weeks into pre-season now so I’m glad that I’ve signed up and I’m going to get ready for the start of the season.
“I’m a high energy player, I like to work hard and get stuck in if I can, I’m not the biggest but I like to get stuck in and hopefully score some goals and assists as well.”
Robinson added: “Technically a very good midfielder who showed his versatility last season by excelling as a right-back for AFC Wimbledon.
“He brings League One experience and adds massive competition for places in a key area of our team.”
The Shrimps have also confirmed that Reading have given permission for keeper Jokull Andresson to figure in tonight’s friendly at Workington AFC and Saturday’s trip to Chorley.
The 19-year-old has been training with Morecambe, having spent an emergency seven-day loan with the club in January.
Thanks for reading. If you value what we do and are able to support us, a digital subscription is just £1 per month for the first two months. Try us today by clicking here