No - it indicates that your ancestors were associated with the village of Sefton which has given its name to a Metropolitan Borough of Merseyside.
However, this does not necessarily mean that somebody with the name isn't Jewish because Judaism passes through the female line whereas surnames pass through the male line. Therefore, if your non-Jewish father met and married a Jewish woman, their children would have been Jewish but would not have had a Jewish surname. This is very common in those countries and regions where Jews have been assimilated into gentile (non-Jewish) society for a long time, especially within port cities such as Liverpool and London, along with cities with large Jewish populations such as Manchester and Gateshead), leading to quite high numbers of people who are halakhically Jewish (Jewish by Jewish law) but - in some cases - unaware of the fact.
Examples of Jews with non-Jewish surnames include the actor and comedian Stephen Fry, the actress Helena Bonham-Carter, singer Jay Kay (Jamiroquai), ska singer Terry Hall (The Specials) and punk guitarist Mick Jones (The Clash).
Amelia Sefton's birth name is Amelia Sarah Sefton.
Jay Sefton's birth name is John Joseph Sefton.
Sefton Park was created in 1867.
Sefton RUFC was created in 1907.
Amanda Sefton was created in 1976.
Sefton Delmer was born in 1904.
Sefton Delmer died in 1979.
Sefton Fincham is 5' 11".
Sefton High School was created in 1961.
Sefton Brancker was born on 1877-03-22.
The area of Sefton Park is 951,011.259264 square meters.
Sefton Henry Parry was born in 1832.