Answer by user707650 for How do I make a single legend for many subplots?

figlegend may be what you're looking for: matplotlib.pyplot.figlegend

An example is at Figure legend demo.

Another example:

plt.figlegend(lines, labels, loc = 'lower center', ncol=5, labelspacing=0.)

Or:

fig.legend(lines, labels, loc = (0.5, 0), ncol=5)