No. As of the writing of this answer (1/4/2021), the only mega-evolvable species are:
- Venusaur
- Charizard (X & Y)
- Blastoise
- Pidgeot
- Beedrill
- Gengar
- Houndoom
- Abomasnow
In a few weeks time, a Chinese announcement leaked that Mega Ampharos will be available.
EDIT: As of December 3rd, 2022, Mega Swampert has been added to Pokemon Go.