Vijaykanth married Premalatha on 31 January 1990 and has two sons Vijayaprabhakaran and Shanmugapandiyan. The latter made his acting debut in the film Sagaptham.
The media has widely publicized an ongoing dispute between Vijayakanth and comedic actor Vadivelu, who was Vijayakanth's co-star in a number of notable films. On 21 September 2008, Vadivelu's residence, located in Saligramam in Chennai, was pelted with stones by a gang leaving several windows and furniture damaged. Vadivelu reported that he suspected that it was Vijayakanth's men who because of a court case which he had filed against Vijayakanth for assault, for which the final court hearing was to take place the following day. The attack may have been set up to prevent Vadivelu from attending the hearing. Filing another case for attempted murder against Vijayakanth, Vadivelu mentioned his interest in competing against him in the next assembly elections and "teaching him a lesson." In response, Vijayakanth told a press meet on that Vadivelu's allegations are based on hearsay. During the legislative assembly elections in Tamil Nadu in 2011, Vadivelu vehemently campaigned for the Dravida Munnetra Kazhagam (DMK) and its alliance. During his public speeches, he predominantly condemned Vijayakanth, whose party, the Desiya Murpokku Dravida Kazhagam (DMDK), allied with the opposition party All India Anna Dravida Munnetra Kazhagam (AIADMK). In a campaign speech in Tiruvarur, Vadivelu stated that "(his) only aim is to sweep out Vijayakanth’s whole team and to campaign vigorously for DMK’s victory". Vadivelu was criticized as being biased, only supporting a DMK-led victory for personal gains and not once mentioning the then-official opposition, the AIADMK, or its leader, J. Jayalalitha. In a turn of events, the election was eventually successful for the AIADMK alliance while Vijayakanth was victorious by a significant margin in his own constituency and vadivelu admitted his defeat.