[2] Nedelev started to play football at his local club and then joined the Botev 2002 Academy in 2004 when he was discovered by the owner Mr. Andrey Pavlov.[8] Nedelev made his official league debut on 25 March 2014, in the 1–3 away loss against Eintracht Braunschweig after coming on as a second-half substitute for Julian Koch.[11] On 28 February, after almost two years since his last goal, Nedelev scored during the 2-2 draw of Botev Plovdiv with PFC Pirin Blagoevgrad and he was elected for "man of the match".[18][19] On 27 August, Nedelev provided an assist for the first goal during the 2-1 home victory over PFC Neftochimic Burgas and again received the award for "man of the match".[36] On 19 April, Nedelev scored from a penalty kick in the final minute and Botev Plovdiv achieved a 0-1 away victory over FC Vereya in the first leg of the semi-finals of the Bulgarian Cup.[38][39][40] On 22 June 2017, Nedelev moved to Botev Plovdiv permanently, signing a contract for 3 years with Mainz 05, keeping the right to take half or more from the next transfer fee of the player.[43] On 9 August, Nedelev scored a spectacular goal from a free kick against Ludogorets Razgrad, and a penalty shootout later, Botev Plovdiv won the Bulgarian Supercup for the first time in its history.[56] On 12 March, the day when Botev Plovdiv celebrated 106 years from its foundation, Nedelev scored a goal for a dramatic 2-4 away win over FC Vereya.[59] On 11 May, Nedelev again made an amazing assist for the winning goal of João Paulo da Silva Araújo and Botev Plovdiv defeated Beroe Stara Zagora with 2-1.[66][67] During the opening round of Parva Liga, on 9 August 2020, Nedelev scored a goal, provided an assist and was selected the man of the match for the 2-0 home derby win over the local rivals Locomotiv Plovdiv.[72] On 28 February 2023, the last day of the transfer window, Botev accepted the offer from Ludogorets Razgrad and Nedelev officially joined the club for 150 000 euros.[75] On 9 September 2014, Nedelev came in as a substitute in the 74th minute and made an assist from a corner kick for the winning goal of Ventsislav Hristov in the opening game of UEFA Euro 2016 qualifying Group H against Azerbaijan.
Todor Nedelev and his teammates from Botev Plovdiv celebrating winning the Bulgarian Football Cup in 2017