The Senate Armed Services Committee will hold the hearing in the fall, she said in a written announcement.
A committee spokeswoman confirmed that there will be hearings but that no specific legislation is under consideration.
"Don't ask, don't tell" is the policy that prevents openly gay troops from serving in the U.S. military.
Former President Clinton instituted it in 1993 as a way of loosening restrictions on gay men and lesbians serving in the armed forces, but its opponents say it does not go far enough.
" 'Don't ask, don't tell' is an unfair, outdated measure that violates the civil rights of some of our bravest, most heroic men and women," Gillibrand said in her statement. "By repealing this policy, we will increase America's strength -- both militarily and morally."
Rep. Patrick Murphy, an Iraq war veteran, urged Obama in early July to repeal "don't ask, don't tell."
Murphy, D-Pennsylvania, appeared at an event with gay, lesbian and straight service members to launch a new initiative.
"We can not afford to wait any longer" for the policy's repeal, Murphy said at the National Press Club in Washington. "Now is the time to change this, when our military is stretched so thin" with wars in Iraq and Afghanistan.
A "Voices of Honor" tour, sponsored by the Human Rights Campaign, will travel across the country, sharing stories of gay, lesbian and straight servicemen and -women in hopes of garnering support for the Military Readiness Enhancement Act, which would repeal the law that established the policy.
Nearly 13,000 service members have been discharged for their sexual orientation since 1993, Gillibrand said.
Since President Obama took office, 287 service members have been discharged for being gay, according to the Servicemembers Legal Defense Network, which supports the repeal.
Obama has said he wants Congress to repeal the law, but gay rights groups have been angered that the president has not done more to hasten the change.
The hot-button issue has been a lightning rod for gay groups urging the Obama administration to push legislation to Congress or put in place a suspension of the program.
And it's not just gay groups urging a change in policy, but former generals and top Defense Department officials.
Former Secretary of State Colin Powell has said that a review is needed.
"Sixteen years have now gone by, and I think a lot has changed with respect to attitudes within our country, and therefore I think this is a policy and a law that should be reviewed," Powell has said.
The military's top uniformed officer, Adm. Mike Mullen, said in July that he is beginning to work with his staff on how a repeal would be implemented. But he advised, with two wars ongoing, that the decision not be hurried.
"When I talk about looking at this in the future, we have a force that's under extraordinary stress, and it's a force that, you know, should this occur, I think we need to implement in a way that is -- that recognizes the challenges and the stress that we're under right now," said the chairman of the Joint Chiefs of Staff. "But, if it does occur, when it does occur, you know, I'll certainly lead it and carry it out."
Defense Secretary Robert Gates recently said he is looking for ways to make the policy "more humane," including letting people serve who may have been outed because of vengeance or a jilted lover.
The Pentagon is still looking at ways to "humanely" apply the law, spokesman Bryan Whitman said Monday.
Gates would "like to change that policy, but there's legislation that impinges on that right now," he said. No concrete steps have been outlined as far as what a humane application of the law might mean for specific cases involving U.S. troops, Whitman said.
But there is plenty of opposition to the repeal. In the spring, more than 1,000 retired officers signed a letter organized by Flag and General Officers for the Military urging Obama to uphold the law.
"We believe that imposing this burden on our men and women in uniform would undermine recruiting and retention, impact leadership at all levels, have adverse effects on the willingness of parents who lend their sons and daughters to military service, and eventually break the all-volunteer force," the letter said.