"I was here to offer my party's thanks to Sonia Gandhi for supporting us," she told reporters here.
The DMK chief M Karunanidhi's daughter was accompanied by senior party leader and former union minister T R Baalu during her meeting with Gandhi.
She was re-elected to Rajya Sabha with Congress support from Tamil Nadu after a contest with actor Vijayakanth's DMDK candidate A R Elangovan on Thursday.
45-year-old Kanimozhi, an accused in the 2G scam, sailed through the contest for a second term with 31 votes after five Congress' MLAs voted in her favour along with two votes each from two smaller parties - Puthiya Thamizhagam and Manithaneya Munnetrak Katchi.