The Preston-born Lonergan, who made 51 appearances in three years at the Macron Stadium, will sign a two year deal with the Cottagers, with the option for a further year extension.
The 31-year old was perhaps a little unfortunate to find himself released by the Whites at the end of the season, in his 29 games during the last campaign, he was on a fantastic run of form for at least 2/3s. However, his form did begin to whither towards the end, and Wanderers were perhaps looking to save money so they can spend more on a true first choice.
Besides, Lonergan deserves first team football, something he'll surely get by the Thames.
Lonergan spoke to the official Fulham website, saying:
"I'm delighted to get it all sorted. I'm happy to be here and I can't wait to get started. It's a very well respected, historic Cub and it's a place where everyone would like to play. We have a lot of potential to hopfully get back to where the Club belongs."
The London club weren't finished there with their signings, as they also announced that they'd captured Ben Pringle, the left midfielder who recently chose to not extend his contract at Rotherham United. This is only of minor interest to Bolton fans, as Pringle was briefly touted as a possible option for Neil Lennon, but it does seem as if the club were never interested in winger with luscious, blond locks.