Solan's history is deeply intertwined with the ancient princely state of Bhagat. The region's original inhabitants were primarily agricultural communities, and the area was renowned for its devotion to Shoolini Mata, the presiding deity after whom the town is named. Each year, the city still celebrates a three-day fair in late June dedicated to the goddess, a tradition dating back centuries.
In the 19th century, during the period of the British Raj, Solan gained prominence when it was established as a cantonment town. The British were drawn to its pleasant climate and strategic location on the route to Shimla, their summer capital. The construction of the Kalka-Shimla Railway in the early 1900s—now a UNESCO World Heritage site—further cemented Solan's importance as a crucial logistical and passenger stop. Solan also became the home of the Mohan Meakin brewery. Originally established in Kasauli in 1855, the brewery was moved to Solan in the 1860s due to the abundance of fresh spring water, making it one of the oldest operational breweries in Asia.
Following India's independence in 1947, the princely state of Bhagat was merged into the newly formed state of Himachal Pradesh. On September 1, 1972, Solan district was officially carved out from the erstwhile Mahasu and Shimla districts, with Solan city becoming its administrative headquarters. In recent decades, the city has undergone significant urbanization, evolving from a quiet hill station into a bustling commercial and educational center. Recognizing its growth, the state government upgraded Solan to a Municipal Corporation in 2020.