Altobello first entered politics in 1985 when he was elected to the council of Scarborough to represent Ward 2, defeating more left-leaning candidate Barry Boyle. At 27, he was the youngest member on the council. He was re-elected with ease in 1988, but in 1991 he faced a fierce election battle against businessman Danny Lovatsis. Nevertheless, he was re-elected.
He opposed the amalgamation of Scarborough, Toronto, and four other municipalities in 1997, but after it occurred he ran for a seat on Toronto city council in Ward 13. The ward structure at the time was such that the two candidates who received the most votes were elected in each riding. He was elected along with Brian Ashton. Fellow Scarborough city councillor Fred Johnson came in third. He has chaired the Planning and Transportation Committee. A centrist, he was aligned with the Liberal Party.
On June 9, 2006, he was appointed a justice of the peace by the Attorney General of OntarioMichael Bryant, effective June 21, 2006.[1] On June 14, 2006, he resigned as a councillor.[2] As a justice of the peace, he presided over the trial of a homeowner accused of renting out the house for short-term tenants.[3][4]