Bidyashagar is a product of East Bengal' youth system. He was part of East Bengal U18 squad that had narrowly lost in the final of the 2016–17 I-League U18.[1] He scored a total of 6 goals in the competition, which includes a goal each against Salgaocar[2] in the semi-final and AIFF Academy in the final. He represented West Bengal in the 2017–18 Santosh Trophy. He scored 4 goals in the tournament.[3][4]
On 9 July 2020, Bidyashagar signed for I-League club TRAU for the 2020–21 I-League season.[7] Bidayashagar made his debut appearance for the club in I-League on 10 January 2020 against Real Kashmir which ended in 1–1 draw.[8] On 24 January 2021, Bidyashagar scored his first goal against Chennai City which ended 2–0 in favour of the Trau FC.[9] He scored his next goal against Churchill Brothers on 29 January 2021 which ended in a 1–1 draw.[10] On 24 February, Bidyashagar scored a brace against Indian Arrows.[11]
He is the second only Indian player to score double hat tricks in a single season, by doing so in a match against Mohammedan and Real Kashmir during the 2020–21 I-League.[12] He ended the season scoring 12 goals,[13] and 1 assist from 15 matches. He was also the top goalscorer in the 2020–21 I-League season.[14] Thus also becoming the fourth Indian player to finish as top scorer in a National League of the country after Bhaichung Bhutia, Raman Vijayan and Sunil Chhetri.
On 28 July 2021, it was announced that Bidyashagar was signed by the Indian Super League club Bengaluru FC on a three-year deal.[16] On 15 August 2021, he debuted for the club in a 1–0 win against Maldivian side Club Eagles in 2021 AFC Cup qualifying play-offs.[17]
Kerala Blasters FC
On 17 August 2022, Kerala Blasters FC announced the signing of Bidyashagar Singh on loan from Bengaluru FC until the end of season.[18] He made his Kerala Blasters debut on 7 October against East Bengal in a 3–1 win by coming as a substitute for Puitea in the 77th minute. He also provided an assist in that game for Ivan Kalyuzhnyi in 81st minute.[19]
Bidyashagar played his first match of the 2023–24 season against Gokulam Kerala FC in the 2023 Durand Cup on 13 August 2023 as a substitute for the goal-scorer Justine Emmanuel, but they lost the match 3–4 at full-time.[20] On 21 August, Bidyashagar scored his first goal for the Blasters and completed his hat-trick against Indian Air Force, helping in a 5–0 victory. He became the first Indian player to score a hat-trick for the Blasters in a major competition and the first hat-trick scorer for the Blasters in the Durand Cup.[21]