Wilkinson's impressive display in kicking all of Toulon's points in their 24-12 victory Saracens in Sunday's Heineken Cup semi-final launched widespread speculation that he would be called up for a third Lions tour.
However, Lions coach Warren Gatland named Owen Farrell and Jonathan Sexton as his only two fly-halves in his squad and told reporters that Wilkinson was committed to Toulon and would not be able to travel with the squad.
The French Top 14 final takes place on the same day as the Lions play the Barbarians in Hong Kong in their opening game on June 1 and Wilkinson's Toulon team are likely to be involved.
"I was phenomenally proud to be considered for the Lions, so it's very disappointing that I'm unavailable," Wilkinson told The Times.
"If Toulon manage to get through to the final of the Top 14, my absolute priority lies with them and helping to get the best out of a team that has been so good to me for so long.
"It is, after all, these guys who have got me to the stage where I could even be considered for the Lions."
Asked if he had contacted Wilkinson to include him in the squad, Gatland said: "I wouldn't have made the call otherwise.
"But we wanted the whole squad to be able to play in Hong Kong and he couldn't make that commitment.
"He said he was struggling with his body and managing things week to week and I think he'd struggle to get through a seven-week tour."
Wilkinson, who turns 34 on May 25, said he would be keen to link up with the squad as a replacement if Gatland called.
"I'll see how I am at the end of the club season and if Warren needs me and I am able to get involved, that would be fabulous."
Wilkinson's Toulon team-mate Gethin Jenkins did make the Lions squad but he was cleared by the club, for whom he is not first choice.