Simply use \hfill before \Box:

\documentclass{article} \usepackage{latexsym} \begin{document} Text\hfill\(\Box\) \end{document} 

Edit: To clarify a bit regarding the comments: this simple command is intended as an answer to the simple question, how to insert a symbol at the end of the line.

The mentioned \Box may lead to the assumption, that the question might be about a proof. The highly upvoted comment of TH. still awaits an answer by the questioner. In the case of a proof it's strongly recommended to use

• amsthm with its proof environment, mentioned by TH., daleif, and Barbara, or

• ntheorem with proper placement of such endmarks even after a displayed math environment or a list.

The answers to Theorem packages: which to use, which conflict? can help in deciding which to use.

Simply use \hfill before \Box:

\documentclass{article} \usepackage{latexsym} \begin{document} Text\hfill\(\Box\) \end{document} 

Edit: To clarify a bit regarding the comments: this simple command is intended as an answer to the simple question, how to insert a symbol at the end of the line.

The mentioned \Box may lead to the assumption, that the question might be about a proof. The highly upvoted comment of TH. still awaits an answer by the questioner. In the case of a proof it's strongly recommended to use

• amsthm with its proof environment, mentioned by TH., daleif, and Barbara, or

• ntheorem with proper placement of such endmarks even after a displayed math environment or a list.

The answers to Theorem packages: which to use, which conflict? can help in deciding which to use.

Simply use \hfill before \Box:

\documentclass{article} \usepackage{latexsym} \begin{document} Text\hfill\(\Box\) \end{document} 

Simply use \hfill before \Box:

\documentclass{article} \usepackage{latexsym} \begin{document} Text\hfill\(\Box\) \end{document} 

Edit: To clarify a bit regarding the comments: this simple command is intended as an answer to the simple question, how to insert a symbol at the end of the line.

The mentioned \Box may lead to the assumption, that the question might be about a proof. The highly upvoted comment of TH. still awaits an answer by the questioner. In the case of a proof it's strongly recommended to use

• amsthm with its proof environment, mentioned by TH., daleif, and Barbara, or

• ntheorem with proper placement of such endmarks even after a displayed math environment or a list.

The answers to Theorem packages: which to use, which conflict? can help in deciding which to use.