She was granted US citizenship in 1999, requiring her to swear an oath renouncing allegiance to any other state. That same year she again stood as an independent, this time winning a seat in the European Parliament, representing Connacht–Ulster. She campaigned on family values and her strong pro-life beliefs. Scallon is opposed to abortion in all cases, In 2013 she said "there is no legal or constitutional obligation for politicians to legislate for the deliberate killing of an unborn child and there is no medical evidence to support this radical change to how we treat our mothers and their children and the taking of an innocent and defenceless human life can never be justified". She was also vocal for her opposition to divorce and same sex marriage, along with a Eurosceptic line on the EU. Scallon refused to associate with any political party despite Fianna Fáil making several approaches for her to join them. On becoming an MEP her eight-year stay in the US came to an end.