John, who was born Reginald Kenneth Dwight, denies the charges, and his lawyer called the suit "baseless."
Jeffrey Wenninger says that John touched him in an "unwelcome" manner over the course of several years after he started working for the singer in 2002 as an off-duty security guard, according to the lawsuit filed in Los Angeles Superior Court. Wenninger, who was a sergeant with the Los Angeles Police Department at the time, said the incidents increased in "frequency and intensity after 2010."
The lawsuit cites three specific incidents in March and April of 2014, all while John was on his way to or from the airport.
Wenninger attempted to resist the unwanted advances, both verbally and physically, but his actions "had no permanent effect" on John's behavior, the suit claims.
Orin Snyder, an attorney for John, said in a statement that Wenninger is "a disgruntled former security officer seeking to extract an undeserved payment."
"These claims are patently untrue and contradicted by numerous previous statements made by this plaintiff," Snyder said. "We will not give into his latest abuse of the legal system."
Wenninger is seeking unspecified damages for, among other things, "physical, mental, and emotional injuries," lost wages and medical costs.
Wenninger was awarded the LAPD's Medal of Valor in 2007
in recognition of his actions 11 years earlier, when he and 12 other officers helped rescue more than 80 elderly people from a burning building.
Wenninger remains employed by the LAPD, the department said Thursday.