You can use the following syntax to set the tick labels font size of plots in Matplotlib:

import matplotlib.pyplotas plt

#set tick labels font size for both axes
plt.tick_params(axis='both', which='major', labelsize=20)

#set tick labels font size for x-axis only
plt.tick_params(axis='x', which='major', labelsize=20)

#set tick labels font size for y-axis only
plt.tick_params(axis='y', which='major', labelsize=20)

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

Example 1: Set Tick Labels Font Size for Both Axes

The following code shows how to create a plot using Matplotlib and specify the tick labels font size for both axes:

import matplotlib.pyplotas plt

#define x and y
x = [1, 4, 10]
y = [5, 11, 27]

#create plot of x and y
plt.plot(x, y)

#set tick labels font size for both axes
plt.tick_params(axis='both', which='major', labelsize=20)

#display plot
plt.show()

Notice that we increased both the x-axis and y-axis tick labels font size.

Example 2: Set Tick Labels Font Size for X-Axis Only

The following code shows how to create a plot using Matplotlib and specify the tick labels font size for just the x-axis:

import matplotlib.pyplotas plt

#define x and y
x = [1, 4, 10]
y = [5, 11, 27]

#create plot of x and y
plt.plot(x, y)

#set tick labels font size for both axes
plt.tick_params(axis='x', which='major', labelsize=20)

#display plot
plt.show()

Notice that we increased just the x-axis tick labels font size.

Example 3: Set Tick Labels Font Size for Y-Axis Only

The following code shows how to create a plot using Matplotlib and specify the tick labels font size for just the y-axis:

import matplotlib.pyplotas plt

#define x and y
x = [1, 4, 10]
y = [5, 11, 27]

#create plot of x and y
plt.plot(x, y)

#set tick labels font size for both axes
plt.tick_params(axis='y', which='major', labelsize=20)

#display plot
plt.show()