Can we override Salesforce standard Actions with Lightning Components?

You can override a standard action with an Aura component in both Lightning Experience and mobile.
You need at least one Aura component in your org that implements the lightning:actionOverride interface. You can use a custom component of your own, or a component from a managed package.
Go to the object management settings for the object with the action you plan to override.
Select Buttons, Links, and Actions.
Select Edit for the action you want to override.
Select Lightning component for the area you want to set the override.
From the drop-down menu, select the name of the Lightning component to use as the action override.
Select Save.