Ryan Seacrest -- Dating a Single Mom!

Ryan Seacrest clearly has a type -- hot and blonde -- but his new girl is different in one big way ... she has a bambino.

The "American Idol" host was spotted out this weekend in NYC with a new blonde -- Renée Hall.

Hall (who is ... shocker!!! ... a model) met Seacrest, fresh off his breakup with model Shayna Taylor, at his 40th birthday party in Napa a few weeks ago.

We're told they met through the Marciano brothers (GUESS founders) and quickly hit it off.

Seacrest took Hall to NYC over the weekend, where they went to the Museum of Modern Art.

As for Hall's 8-year-old son, she's proud and loud, posting pics all over her Instagram page.

Ryan would be a cool stepdad, right?