The pair were voted back in by the public this week following their evictions by the contestants earlier in the series.
Fans had a choice of four potential contestants to join the show with Mike and Sam winning the poll and entering the villa tonight.
And here's all you need to know about the new, old Islanders...
Mike aka Muggy Mike is a 24-yer-old Semi-Pro Footballer from London.
"I just think I look different to all of them. Tall, dark and handsome – which is what most of the girls have said they are looking for," a confident Mike said today ahead of his entrance.
On applying for the show, Mike continued: "It’s a one off experience – it’s an amazing villa, with good looking guys and girls. It looks really fun and this is the first time in my life I haven’t had any commitments.
"I don’t have a girlfriend, and I feel like I’m mature enough to do it."
He continued: "My mates know I’m quite selective. Girls would probably think I’m a player but I’m not. I’m very honest and say it exactly like it is. Sometimes that doesn’t work in my favour."
Sam is a 21-year-old oil rig worker from Middlesbrough.
Sam says: "I'm a little bit different to everyone else. I don't beat around the bush: I'm going on to win the show, not to make friends!
"At the end of the day, it's a competition. I'm there to find love, yes, but I'm also there to win. And if I have to step on someone's toes to do that, then I will do!"
He adds of Love Island: "I've watched it for the past few years and every time I've watched it I've thought, 'I could do that myself!’
"The last time I watched it, I was in a relationship. Then I became single in September when they were advertising, so it's kind of the first chance I've had to have a go at it. I actually am going to find love! I'm ready for that."
Love Island 2017 continues nightly at 9PM on ITV2.