Siddiqui started his career as a correspondent for the "Hindustan Times" before shifting to the TV Today Network. He switched to photojournalism and joined Reuters as an intern in 2010. Siddiqui had since covered the Battle of Mosul (2016–2017), the April 2015 Nepal earthquake, the 2015 Rohingya refugee crisis, the 2019–2020 Hong Kong protests, the 2020 Delhi riots, and the COVID-19 pandemic among other stories in South Asia, Middle East and Europe.