The 21-year-old pens a one-year deal with the Iron after leaving Championship side Blackburn Rovers this summer, and the former Manchester United academy defender is seeking to make a big impact for Neil Cox's side.
He said: "I'm delighted to join the club and I'm really grateful to the gaffer for giving me an opportunity here. I'm really looking forward to it and the opportunity to pay back the trust which has been put in me with my performances. I'm excited for the season and think we can have a really positive year.
"From day one of my trial, I was made to feel welcome by the lads. It's a really good group with talented players, but at the same time they're good professionals and people to learn from as well."
Thompson got his first 45 minutes of pre-season in the 4-1 away friendly victory at Barton Town last Saturday, where he was referred to as 'Trialist B', and is looking forward to more game time in the upcoming friendlies as the Iron prepare for the new season.
He added: "I enjoyed the game on Saturday. It's been a long summer keeping myself fit but it was good to play at the weekend, get an assist (for Devarn Green's goal) and contribute. It was a really good effort from all the players and helped get us that bit sharper going into the season.
"I'm really excited by the challenge. I feel I've learned a lot from my experiences at Blackburn and when out on loan in the National League and National League North (to Fylde and FC United of Manchester respectively). I've played for Northern Ireland in the U21s in recent times, and have played against some really good players. For example Serie A or Bundesliga players. It was a good experience and helps you grow and improve as a player.
"I hope they can all stand me in good stead and I'm confident I can contribute to the team this year in a really positive way. I've always seen myself as a physical player who can get up and down the pitch, not afraid to put my foot in and try to dominate the winger I'm playing against."
Thompson will battle with fellow left-back Mason O'Malley for that particular position in the team and says the competition for places will bring the best out of everybody.
He continued: "I've seen Mason in training and he's a really good player with a good left-foot. At the end of the day, you want competition for places in all areas of the pitch. It only drives you on and improves the standard of training, giving the gaffer different options all over the pitch.
"I want to contribute right from the start of the season and believe I can do that. Consistency of performance is a big thing and as a defender it's not so much about stats but what you deliver on the pitch."
See much more from Lewis Thompson and Neil Cox on iFollow Iron.