Can You Use align* Inside enumerate* in LaTeX?

align* and enumerate* have different jobs: align* creates a displayed, multi-line equation, while enumerate* from the enumitem package creates a list whose items run inline with the surrounding text. That mismatch is why placing one directly inside the other can cause errors or awkward layout.

For a list item that needs a displayed equation, use the ordinary enumerate environment. The star in align* means the equations are unnumbered; the star in enumerate* denotes an inline list.

Use ordinary enumerate for displayed equations

This minimal example compiles with the amsmath package. Loading enumitem as well is optional unless you need its list customization features.

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\begin{enumerate}
  \item Simplify the expressions:
    \begin{align*}
      f(x) &= x^2 + 1 \\
      g(x) &= 2x - 3
    \end{align*}
  \item Compare the two results.
\end{enumerate}
\end{document}

Each \item in ordinary enumerate starts a vertical list item. LaTeX can therefore place the align* display within that item. The equation block is centered in the available text area, not positioned directly after the item label; that is normal display-math behavior.

If you want to customize the appearance or spacing of this numbered list, load enumitem and configure ordinary enumerate. You do not need to switch to enumerate* just to use that package.

If the list must be inline

An inline list is appropriate when each item is short, such as a sequence of expressions in a sentence. Use inline math for each item:

\documentclass{article}
\usepackage{amsmath}
\usepackage[inline]{enumitem}

\begin{document}
The results are \begin{enumerate*}
  \item $f(x)=x^2+1$,
  \item $g(x)=2x-3$.
\end{enumerate*}
\end{document}

For a multi-line mathematical expression that should remain within one inline item, use aligned inside math mode. Unlike align*, aligned is designed to be nested inside another math environment:

\begin{enumerate*}
  \item $\begin{aligned}
    f(x) &= x^2 + 1 \\
    g(x) &= 2x - 3
  \end{aligned}$
\end{enumerate*}

This makes the aligned block part of the inline item, so it behaves like an in-text mathematical object rather than a full-width display. It may look cramped or disrupt line spacing if the expression is tall. For substantial derivations, ordinary enumerate with align* is usually clearer.

Common mistakes

• Confusing the two stars: align* is an unnumbered display environment from amsmath; enumerate* is an inline-list environment from enumitem.
• Expecting align* to act like inline math: It creates a display and cannot simply be dropped into a horizontal inline list. Use ordinary enumerate or aligned in math mode instead.
• Using aligned without math mode: aligned is not a complete display environment. Wrap it in $...$, \(...\), or another suitable math environment.
• Forgetting the package: align* requires amsmath. The inline enumerate* environment requires enumitem configured for inline lists (for example, with the inline option).

Choosing the right combination

What you need	Use
Numbered or bulleted vertical items with displayed equations	enumerate or itemize with align*
A short list that runs within a paragraph	enumerate* with inline math
A compact aligned expression inside an inline item	enumerate* with aligned inside math mode

The main fix is to choose the list environment based on layout: use a vertical list when an item contains a display, and an inline list when its items fit naturally into running text.