His elder brother Gobind Thapa was an Assam state-level medal winning boxer;[6] Mike Tyson's bouts also inspired him to take the sport seriously.

[9] While signing Thapa, Viren Rasquinha, the chief operating officer of Olympic Gold Quest said: Shiva is an enormous talent.

[9]At the 2008 Children Asia International Sports Games that was held in Yakutsk (Russia) Shiva Thapa won a bronze medal in his category.

[23] In July 2013, Shiva became the youngest Indian to win a gold at the Asian Confederation Boxing Championship at Amman, Jordan.

Maneesh Bahuguna, the CEO of his managing firm, Anglian Medal Hunt Company was quoted as having said, "Shiva’s outstanding achievements made him an undisputed choice for WSB.

[citation needed] Shiva Thapa became only 3rd Indian to win a medal at AIBA World Boxing Championships when he won bronze.

Shiva Thapa qualified for the 2016 Rio Olympic in the Men's 56 kg event, but failed to move beyond the first round after suffering a 0–3 defeat to eventual Gold medalist Robeisy Ramírez of Cuba.

[38][39] Shiva Thapa won silver at 2017 Asian Amateur Boxing Championships in Tashkent after an injury-forced loss to second seed and local favourite Elnur Abduraimov.

[40] 2019 He won gold medal at 2019 Tokyo Olympic test event by defeating Kazakhstan's national champion and Asian bronze-winner Sanatali Toltayev 5-0.

He is employed with Oil and Natural Gas Corporation Ltd.[41] He is supported by Olympic Gold Quest and Anglian Medal Hunt Company.