Direct Action Everywhere spokesman Matt Johnson identified the protester as 30-year-old Priya Sawhney of Berkeley, California.
Sawhney was held on suspicion of misdemeanor trespassing and may face more serious charges, Las Vegas police Officer Laura Meltzer said.
Bezos was explaining plans to send satellites into space when the woman appeared on stage.
Johnson said Sawhney was protesting conditions at a California poultry farm that supplies Amazon.
She never got close to Bezos, who remained seated opposite a moderator to whom he joked, "Do you have a response to that?"