In August 2008, the Bulgarian national coach Plamen Markov called Stanislav in Bulgaria national football team in a match against Bosnia and Herzegovina national football team. Manolev made his official debut and Bulgaria won the match as a guest. Manolev was a part of the Bulgaria national football team in the World Cup 2010 qualifiers against Italy and Montenegro, but remained an unused substitute. He played 45 minutes in the second half of the friendly between Bulgaria and Serbia in November 2008. He was in the starting 11 in the next two games against the Republic of Ireland and Cyprus. He scored his first goal for Bulgaria in a 2014 FIFA World Cup qualification match against Italy that finished 2–2.