º is a masculine ordinal indicator, used in Portuguese and Spanish. It is a raised lowercase o, which is the masculine adjective's ending. For example, "primero" (meaning "first") is written as 1º or 1o, the same way it is written in English as 1st.

It is often confused with the ° degree symbol, whose circle's border has uniform width; whereas in most fonts, the ordinal indicator has thick borders on the sides in some fonts, and may be underlined, such as o.

The following requires the presence of certain fonts, likely to be present in a computer with Windows installed.
Masculine ordinal indicatorDegree sign
º º º º º º º ° ° ° ° ° ° °

See also: ª