By default, the title of plots in ggplot2 are left-aligned.

However, you can use the following methods to change the title position:

Method 1: Center the Title

some_ggplot +
  theme(plot.title = element_text(hjust = 0.5))

Method 2: Right-Align the Title

some_ggplot +
  theme(plot.title = element_text(hjust = 1))

Method 3: Adjust Title Position Vertically

some_ggplot +
  theme(plot.title = element_text(vjust = 10))

The following examples show how to use each method in practice with the built-in mtcars dataset in R.

Example 1: Center the Title

The following code shows how to create a scatterplot in ggplot2 and center the title using the hjust argument:

library(ggplot2)

#create scatterplot with centered title
ggplot(data=mtcars, aes(x=mpg, y=wt)) +
  geom_point() +
  ggtitle("Plot Title") +
  theme(plot.title = element_text(hjust = 0.5))

Notice that the title is aligned in the center.

Example 2: Right-Align the Title

The following code shows how to create a scatterplot in ggplot2 and right-align the title using the hjust argument:

library(ggplot2)

#create scatterplot with right-aligned title
ggplot(data=mtcars, aes(x=mpg, y=wt)) +
  geom_point() +
  ggtitle("Plot Title") +
  theme(plot.title = element_text(hjust = 1))

Notice that the title is aligned to the right.

Example 3: Adjust Title Position Vertically

The following code shows how to create a scatterplot in ggplot2 and move the title higher up using the vjust argument:

library(ggplot2)

#create scatterplot with title moved higher up
ggplot(data=mtcars, aes(x=mpg, y=wt)) +
  geom_point() +
  ggtitle("Plot Title") +
  theme(plot.title = element_text(hjust = 1, vjust = 3))

Notice that the title is moved higher up.

You can also provide a negative value to the vjust argument to move the title lower down:

library(ggplot2)

#create scatterplot with title moved down
ggplot(data=mtcars, aes(x=mpg, y=wt)) +
  geom_point() +
  ggtitle("Plot Title") +
  theme(plot.title = element_text(hjust = 1, vjust = -10))

Notice that the title is now moved inside the plot.

Additional Resources

The following tutorials explain how to perform other common operations in ggplot2:

How to Change the Legend Title in ggplot2
How to Rotate Axis Labels in ggplot2
How to Fix in R: could not find function “ggplot”