How to move the legend to outside of a Seaborn scatterplot in Matplotlib?

To move the legend outside of a Seaborn scatterplot, you need to use the bbox_to_anchor parameter in the legend() method. This allows precise control over legend positioning relative to the plot area.

Basic Setup

First, let's create a sample dataset and generate a scatterplot ?

import matplotlib.pyplot as plt
import pandas as pd
import seaborn as sns

# Set figure size
plt.rcParams["figure.figsize"] = [8, 5]
plt.rcParams["figure.autolayout"] = True

# Create sample data
df = pd.DataFrame({
    'x_values': [2, 1, 4, 3, 5, 2, 6],
    'y_values': [5, 2, 1, 4, 3, 6, 2],
    'category': ['A', 'B', 'A', 'C', 'B', 'C', 'A']
})

# Create scatterplot with hue for different categories
sns.scatterplot(data=df, x='x_values', y='y_values', hue='category', s=100)

# Move legend outside the plot
plt.legend(bbox_to_anchor=(1.05, 1), loc='upper left')
plt.tight_layout()
plt.show()

Different Legend Positions

You can position the legend in various locations outside the plot ?

import matplotlib.pyplot as plt
import pandas as pd
import seaborn as sns

# Create sample data
df = pd.DataFrame({
    'x_values': [2, 1, 4, 3, 5, 2, 6, 4],
    'y_values': [5, 2, 1, 4, 3, 6, 2, 5],
    'category': ['Group A', 'Group B', 'Group A', 'Group C', 'Group B', 'Group C', 'Group A', 'Group B']
})

fig, axes = plt.subplots(2, 2, figsize=(12, 8))

# Right side (outside)
sns.scatterplot(data=df, x='x_values', y='y_values', hue='category', ax=axes[0,0])
axes[0,0].legend(bbox_to_anchor=(1.05, 1), loc='upper left')
axes[0,0].set_title('Legend on Right')

# Bottom (outside)
sns.scatterplot(data=df, x='x_values', y='y_values', hue='category', ax=axes[0,1])
axes[0,1].legend(bbox_to_anchor=(0.5, -0.15), loc='upper center', ncol=3)
axes[0,1].set_title('Legend at Bottom')

# Top (outside)
sns.scatterplot(data=df, x='x_values', y='y_values', hue='category', ax=axes[1,0])
axes[1,0].legend(bbox_to_anchor=(0.5, 1.15), loc='lower center', ncol=3)
axes[1,0].set_title('Legend at Top')

# Left side (outside)
sns.scatterplot(data=df, x='x_values', y='y_values', hue='category', ax=axes[1,1])
axes[1,1].legend(bbox_to_anchor=(-0.15, 1), loc='upper right')
axes[1,1].set_title('Legend on Left')

plt.tight_layout()
plt.show()

Key Parameters

With Style Customization

You can also customize the legend appearance while positioning it outside ?

import matplotlib.pyplot as plt
import pandas as pd
import seaborn as sns

# Create sample data
df = pd.DataFrame({
    'x_values': [1, 2, 3, 4, 5, 6, 7, 8],
    'y_values': [2, 5, 3, 8, 7, 1, 6, 4],
    'size_values': [50, 100, 150, 200, 120, 80, 180, 90],
    'category': ['Alpha', 'Beta', 'Gamma', 'Alpha', 'Beta', 'Gamma', 'Alpha', 'Beta']
})

plt.figure(figsize=(10, 6))

# Create scatterplot with both hue and size
sns.scatterplot(data=df, x='x_values', y='y_values', 
                hue='category', size='size_values', sizes=(50, 200))

# Customize legend and move outside
plt.legend(bbox_to_anchor=(1.05, 1), loc='upper left', 
          frameon=True, fancybox=True, shadow=True)

plt.title('Scatterplot with External Legend')
plt.tight_layout()
plt.show()

Conclusion

Use bbox_to_anchor with coordinates like (1.05, 1) to position legends outside plots. Combine with plt.tight_layout() to ensure proper spacing and prevent legend cutoff.