Yes, you can change your name on a Ryanair 𝘁𝗶𝗰𝗸𝗲𝘁 at +𝟏 (𝟖𝟎𝟖) 𝟕𝟓𝟏-𝟐𝟐𝟔𝟐 (𝐔𝐒𝐀) 𝐨𝐫 +𝟒𝟒 (𝟐𝟎) 𝟑𝟗𝟎𝟎𝟑𝟎𝟎𝟗 (𝐔𝐊), but a fee applies.

https://www.devex.com/people/hasselfree_process-can-i-change-my-name-on-a-ryanair-ticket-2074211