Tulsi Vivah is the ceremonial marriage of the Tulsi (holy basil) plant to the Hindu god Shaligram or Vishnu or to his avatar, Sri Krishna. The Tulsi wedding signifies the end of the monsoon and the beginning of the wedding season in Hinduism.

The ceremonial festival is performed anytime between Prabodhini Ekadashi (the eleventh or twelfth lunar day of the bright fortnight of the Hindu month of Kartik) and Kartik Poornima (the full moon of the month). The day varies regionally.