Since you are going to use this on a login page. Here is a code I used in a Login page using Material-UI

MUI v5

<Grid
  container
  spacing={0}
  direction="column"
  alignItems="center"
  justifyContent="center"
  style={{ minHeight: '100vh' }}
>

  <Grid item xs={3}>
   <LoginForm />
  </Grid>   
   
</Grid> 

MUI v4 and below

<Grid
  container
  spacing={0}
  direction="column"
  alignItems="center"
  justify="center"
  style={{ minHeight: '100vh' }}
>

  <Grid item xs={3}>
    <LoginForm />
  </Grid>   

</Grid> 

this will make this login form at the center of the screen.

But still, IE doesn't support the Material-UI Grid and you will see some misplaced content in IE.

As pointed by @max, another option is,

<Grid container justifyContent="center">
  <Your centered component/>
</Grid>

Please note that versions MUIv4 and below should use justify="center" instead.

However, using a Grid container without a Grid item is an undocumented behavior.

Hope this will help you.

Another option is:

<Grid container justify = "center">
  <Your centered component/>
</Grid>

You can do this with the Box component:

import Box from "@material-ui/core/Box";

...

<Box
  display="flex"
  justifyContent="center"
  alignItems="center"
  minHeight="100vh"
>
  <YourComponent/>
</Box>