The France international striker was forced to wait until late in the winter transfer window before seeing his future resolved.
A move away from Emirates Stadium had been mooted for some time, and eventually all of the pieces fell into place as Pierre-Emerick Aubameyang linked up with the Gunners and Michy Batshuayi departed Stamford Bridge for Borussia Dortmund.
Giroud is delighted to have joined a team of proven winners and has vowed to give his all to the ongoing pursuit of more major honours.
The 31-year-old frontman told the Blues’ official website: “Chelsea was the perfect team for me, the perfect club.
“It’s the Premier League, it’s the club which has won the most titles in the last 10 years, it’s a massive club. I’m very proud and happy to be here.
“People want you to wear the shirt and give the maximum. I know I will have to be efficient, assist sometimes, score sometimes.
“We don’t have too much time for integration but I feel very good and the boys have been very good to me.”
Defending champions Chelsea have seen their Premier League crown slip, with Manchester City dominating the battle for domestic supremacy in 2017-18.
Antonio Conte’s side are, however, still in the hunt for FA Cup glory, a top four finish and another Champions League triumph – with a heavyweight tie against La Liga giants Barcelona awaiting at the last-16 stage of that competition.
“We’re going to take the games step by step,” added Giroud.
“Firstly we want to qualify in the FA Cup and then we have three big games to come, Barcelona in the Champions League and then the two Manchester clubs away, that’s why we need the confidence high. We need to keep it up and build momentum.”
Chelsea returned to winning ways in their last outing against West Brom, with Giroud contributing his first assist as the Blues got back on track after a recent wobble.