After completing his secondary education in 1994, Lal attended St. Stephen's College of the University of Delhi for a bachelor's degree in economics.

Before he joined Eicher Motors, his father, Vikram, sent him to Europe to interact with Royal Enfield motorcycle importers in the continent.

[12][9] Initially, Lal's responsibility as CEO of Royal Enfield, which was on the verge of being sold due to the company's problems, was to fix the unit's products, financial and operational issues.

[12][16] Lal's reason for forming a joint venture with Volvo was to become one of the largest competitors in India's truck market.

[18] In August 2021, during the annual general meeting of Eicher Motors, shareholders of the company rejected Lal's reappointment as MD due to disagreements about an increase in his remuneration.

[21] Siddhartha Lal relocated from Delhi[22] to London,[14] in August 2015, in order to be close to Royal Enfield's new R&D centre in Leicestershire.