What's a good machine learning model for an univariate data set?
Your question is not very specific. I am assuming that you are looking for the full solution (Language, package, function, template).  So with that in mind I'll point you to the following question:
Polynomial regression using scikit-learn

Half way down the answers is a solution by Salvador Dali for:

Language: Python
Package:scikit-learn
Function: linear_model.LinearRegression()