The 31-year-old scored 22 times for the Ayrshire club in his second spell during the 2013/14 season and consequently earned a move to Ibrox.
He disappointed on his return there though having scored 127 goals for Rangers between 2006 and 2010, netting on just 10 occasions in 43 matches.
Striker Boyd began his career at Kilmarnock and will be hoping to add to the 92 goals from his first two stints at Rugby Park.
The 18-times capped forward has also played in England with Middlesbrough and Nottingham Forest as well as in Turkey with Eskisehirspor and the USA with Portland Timbers.
Boyd is Kilmarnock’s fourth summer signing after Scott Robinson, Jamie MacDonald and Kallum Higginbotham and said: “I am delighted to have signed once again for Kilmarnock. This is a great club for me.
“I feel I have done well here in the past and I am looking forward to getting fit and scoring more goals this time round. I really want to help the Club get back to the top six where it belongs.”
Boyd saw new manager Gary Locke regularly last year as he continued to return to Rugby Park to help with coaching youngsters at the club.
The striker also revealed he had offers to go abroad again but wanted to stay local for family reasons.
He said: “We’ve had plenty of discussions and I’m delighted to be back and hopefully I can kick on from where I left a couple of seasons ago.
“There were a couple of offers abroad but once she (his wife) put her finger down that was me. It is a great opportunity for me to come back.
“I want to spend time with my kids, which is the most important thing. If you are happy at home then you’re happy on the field as well.”
Although delighted to be back at his first club, Boyd said he had no regrets over his return to Rangers last year.
“It didn’t work out but it is in the past. I am thankful for the opportunity from (former Gers manager) Ally McCoist to take me back there.
“For a Kilmarnock fan playing anywhere else, if Kilmarnock come and give you the opportunity to go there you’re going to go. It is the same with me. I might’ve been playing with Kilmarnock but I was a Rangers fan so the opportunity to go back to Rangers was always going to appeal to me.”
And Boyd revealed that he thinks it would be good for Scottish football to see old club back in the top flight.
Asked if Rangers can win promotion this season, he said: “I hope so. Anyone in Scottish football would be crazy to sit and say they don’t want them back up.
“With Rangers it gives Scotland a bigger profile, it brings more money to the other clubs and the Rangers fans deserve to be up because they’ve stuck by the club through thick and thin.”
Although Locke is also keen on another player who has left Rangers – their former captain Lee McCulloch – no deal has been done there as yet.
Locke wants to recruit the 37-year-old in a playing capacity and also as his assistant after the former Scotland international completed his UEFA Pro Licence.
While talks between the two have taken place, no agreement has been reached with McCulloch.