If you're using Ubuntu 18.04 LTS or 20.04 LTS on amd64, arm64, armhf or i386, then you can use the longsleep/golang-backports PPA and update to Go 1.15.

sudo add-apt-repository ppa:longsleep/golang-backports
sudo apt update
sudo apt install golang-go

Note that golang-go installs latest Go as default Go. If you do not want that, install golang-1.15 instead and use the binaries from /usr/lib/go-1.15/bin.

If that's too new for you, try: (Ubuntu 19.04 max)

$ sudo add-apt-repository ppa:gophers/archive
$ sudo apt update
$ sudo apt install golang-1.11-go

Note that golang-1.11-go puts binaries in /usr/lib/go-1.11/bin. If you want them on your PATH, you need to make that change yourself.

Using snaps also works quite well:

$ sudo snap install --classic go

A restart may or may not be required for the command to be recognized depending on your system.

Using getgo (proof-of-concept command-line installer for Go):

curl -LO https://get.golang.org/$(uname)/go_installer && chmod +x go_installer && ./go_installer && rm go_installer