You can use the following basic syntax to add a title to a subplot in Matplotlib:

ax[0, 1].set_title('Subplot Title')

The following examples shows how to use this syntax in practice.

Example 1: Add Titles to Subplots in Matplotlib

The following code shows how to create a grid of 2×2 subplots and specify the title of each subplot:

import matplotlib.pyplotas plt

#define subplots
fig, ax = plt.subplots(2, 2)

#define subplot titles
ax[0, 0].set_title('First Subplot')
ax[0, 1].set_title('Second Subplot')
ax[1, 0].set_title('Third Subplot')
ax[1, 1].set_title('Fourth Subplot')

Notice that each subplot has a unique title.

Example 2: Add Customized Titles to Subplots in Matplotlib

We can use the following arguments to customize the titles of the subplots:

• fontsize: The font size of the title
• loc: The location of the title (“left”, “center”, “right”)
• x, y: The (x, y) coordinates of the title
• color: The font color of the title
• fontweight: The font weight of the title

The following code shows how to use these arguments in practice:

import matplotlib.pyplotas plt

#define subplots
fig, ax = plt.subplots(2, 2)

#define subplot titles
ax[0, 0].set_title('First Subplot', fontsize=18, loc='left')
ax[0, 1].set_title('Second Subplot', x=.75, y=.9)
ax[1, 0].set_title('Third Subplot', color='red')
ax[1, 1].set_title('Fourth Subplot', fontweight='bold')

Using these various arguments, you can customize the subplot titles to look however you’d like.

Additional Resources

How to Adjust Title Position in Matplotlib